Maybe farfetched right now, but later could be a reality. That is usually how it always goes, first animals then humans. If you take a problem ignore it, downplay it, or deny it is there, and then throw it away. It will come back and bite you in the ass really hard later
Speaking from experience. You would benefit from therapy (AT LEAST) and the thing is, that there are ways to get the therapy you need without your parents knowing, you can get it through the school and I am pretty sure if you have a good reason for it or if you just ask them not to, they won't tell your parents unless absolutely necessary. Or you can tell your parents you need therapy and (since you are a liar and probably a good one from your experience in it) you could just lie about why and then proceed to talk to your therapist about your actual problems. A therapist is not allowed to tell anyone about what you tell them unless you prove you are a threat to yourself or others either by action or words. Otherwise they legally cannot say anything to anyone. Also, with issues like these. I would be careful about lying about your mental health to doctors so much. Because once you want help for something real kinda like the real thing happening right now. 9 chances out of 10, they will not take you seriously at all.
You don't want professional help but from the sounds of it you need it and have needed it for a while now. Life and living life is about 40% what you want to do I would go as far as to say it is about 20% what you want to do, the rest is what you need to do. Trust me when I say this.
If you don't get this problem figured out at some point you are either gonna seriously regret it later or get yourself into a deeper hole of trouble before you even have a chance to regret it.
In this situation the best step to take towards anything, is therapy. Some sort of professional help. I am not saying you aren't in a clear enough mindset to help yourself (though I personally don't think you are) but if you are now, what happens when you are stuck in such an unstable and unclear headspace you can't even get yourself help let alone help yourself, it would just be a downward slide from there. You even said, you don't even know what the problem is. You can't fight something you don't even know what is. And you would have an even harder time and a more dangerous time trying to figure out what it is without someone who is actually able to figure that out.
Before I end this long ass comment I wanna make this clear. I am a person who generally doesn't care. If I am speaking honestly I don't care about any of the bad things you did, I am no angel either, can't say I did any of what you did but I also (as established already) don't care enough about what you did to judge it.
Put simply Get your help. Stop (actively trying to get a label) because few people will care, it is fruitless for whatever high you get from it, dangerous, and will seriously sabotage you when you actually have problems and then you will be screwed.
And be very careful about the medications unless you (ACTUALLY NEED THEM) because honestly doing them the way you are now will just accelerate you into a deeper hell you probably won't get out of, or worse kill you or close to it.
Good for you for trying to help yourself, recognizing these issues, but if it were me I would say to get a professional to help you.
Good luck