Okay. Here's some personal thoughts that I hope you will find helpful. This is more about things to think about if you go ahead and take action. You've already mentioned SARC, so I'll assume at this point that you have access to a counselor who is familiar with your circumstances.
So at this point, I think you should speak with your counselor about possible emotional and psychological impacts of pursuing the matter. This will help you to determine if you think you're in the right place emotionally to go through with it. Also, if you haven't told your family yet, your counselor can help in that area too. If you go ahead, family will be very important because you will need a strong support base.
The next thing would be to speak to a lawyer to find out exactly what your options are, what to expect in regard to dealing with the Police and how the court process will work. Again, your counselor may be able to refer you to someone with experience in the right areas. Once you've done that, you should then be able to decide how you want to proceed.
One important thing to know right now is that you don't need to rush. Counselor -> Family -> Lawyer -> Decision. The decision to act or not and what any action will be, is ultimately yours and you need to be comfortable with it - whatever it is. So again, don't rush.
If you do act remember to always stay positive, but at the same time, prepare for a worst case scenario. There will be good days and bad days and as with anything, there is always the possibility that the outcome of all of this won't go your way. It is extremely important that you not only realise this, but accept it before you even start. You need to have belief in yourself that you will be able to cope with the bad days and also with a loss if that should eventuate. So the message here is "prepare" for the worst, but "stay" positive. A good way to look at it is "I know I am doing the right thing by pursuing this, so no matter what happens, I have no regrets."
Along the same lines, it would be beneficial to you if you commit now to having as much faith in the system as you can muster. Like having belief in yourself, having belief in the system and committing to accepting whatever the outcome is, will definately help you to take back control of your life and move on once this is all over. So similar to above, this is about "once it's over, it's over - and I'm not going to look back." This is not an easy thing to commit to, but if you can do it on some level, then it is going to help in a big way win or lose.
There's also a few things to note about your particular case...
In years gone by, the legal system was inclined to give benefit of the doubt to the accused when it came to the victim being impaired (drunk, high, etc). Nowadays however, the system has reversed this line of thinking which significantly strengthens your case. The general principle now, is that a person is not capable of free will if they are incapacitated, therefore they are not capable of giving consent.
How the states word their legislation however is very different. Each state has a bunch of different offences with each one having it's own criteria. In WA, there is an offence called "Incapable person, sexual offences against", which states
... an incapable person is a reference to a person who is so mentally impaired as to be incapable -
(a) of understanding the nature of the act the subject of the charge against the accused person; or
(b) of guarding himself or herself against sexual exploitation
So impairment by alcohol or drugs could fall under (a), (b) or both and I have no doubt that "drifting in and out of consciousness" would render you an "incapable person" under this definition. His actions therefore would consitute an offence under this section (s330 WA Criminal Code Compilation Act.)
(NSW deals with intoxication differently. Instead of there being a seperate offence, it is dealt with in the section that actually defines "consent". It basically states that "substantially intoxicated by alcohol or any drug" is "grounds on which it may be established that a person does not consent". This means that intoxication can be a factor in any offence where consent is a factor. So the principle is the same, but how WA and NSW implement the principle in regard to how the legislation is worded is very different.)
the main incriminating messages from the perpetrator are ones where he acknowledges that I was high, that he only wanted to have sex with me high because I was more vulnerable and was cold to his responses sober
This is an admission that he was well aware of your incapacity and also shows the possibility of premeditation. Speaking of which...
"I wanted to make sure I was in the right frame of mind to decide if anything was going to happen between us"
If I am reading this one in the correct context, in that this is a direct quote of one of the text messages, then this refers to his state of mind and him making a decision. If that's the case, then this could be evidence of premeditation - in which case he's in even more trouble and would likely result in a much harsher penalty.
But he never outright admits to it being r**e or me not giving consent, so I don't know if that implication is enough. It's also difficult because of the messages with me calling it consensual sex and I feel like denial wouldn't be taken as seriously.
Don't be too concerned about this. What matters is what took place at the time of the incident. Just make sure that you don't try to hide this from the lawyers or Police when the time comes. Tell them everything so that they don't get ambushed later on. They'll know how to deal with it - that's their job.
Also don't forget that in your emotional state, you may have been influenced or even manipulated by others, particularly in the early days and particularly in regard to keeping it quiet. The more people you speak to, the more your behaviour and statements can be influenced when you are so distressed. There is also the denial factor that you already mentioned.
So don't worry too much - the lawyers, prosecutors etc will know how to deal with all of that.
I kept a diary and a few video diaries detailing how I was pushing him away and he kept holding my arm down, I have
Tafe attendance records, I am currently seeking trauma therapy at SARC.
This can all be used as evidence. Don't hold anything back.
All up, I think your case is a lot stronger than you think, so I recommend Counselor -> Family -> Lawyer -> Decision, and I sincerely hope the rest of the equation will look something along the lines of Police -> Court -> Conviction.
Sorry for the long post - I know it's a lot to take in, but I hope it helps in some small way. You have a lot to think about, so take your time and consider everything you do from here on very carefully - one step at a time.
Ultimately, this all leads to you making one massive decision - and you being comfortable with that decision, is the most important thing of all. You come first - everything else is secondary.
