I know it doesn't seem like it when people say it, but I know how you feel - and how frustrating it is for you.
My parents had my computer locked with a program called Net Nanny, all because he found out (through snooping) that I had downloaded and installed MSN and created a hotmail account to talk to my friends. Obviously the first thing that he was worried about was "OMG she is probably talking to 50 year old pedos", so I had to have a parent 'unlock' my computer every 5 mins, my internet browsing history would be sent to him, and my MSN conversations built up in a remote archive for easy viewing (I had no idea about the last one). I could t even play Sims on my own because the computer wouldn't let me open any program without a password, and would quit the game as it required a password every 5 mins.
It was only really up to very recently (like, the middle if the HSC) that he eased up a bit. He still got a little over protective if he found out that I walked 200m down the road on my own to get some cheese for my lunch, but it has gotten better over time.
Now that I'm 18 and starting uni, he's even acknowledged that he will just have to trust me as he can't keep tabs on me 24/7 anymore. He was brought up in an extremely strict Italian family, so that was really his way of showing his love.
And as someone who has been down the dark tunnels of mental illness, I'm going to please urge you not to take a road as drastic as suicide. Sometimes all it takes is time for you and your parents; for you to mature even more and for them to realise that you are an adult and capable of making adult decisions.
Honestly there have been pints in my life that I had been so ready to take my life, even planning and writing letters, etc. I would lash out at my family and be either angry or sad all the time because I just hated myself and had no hope that anything would get better. I yelled this to my parents one night in a fight and they sent me straight to a psychologist. At first I hated it and wouldn't try at all, but then I woke up a little and began to open up to her. She helped me through a lot of my personal demons, and just general things. It was great to have someone there to rant to during the HSC that wouldn't give me the "well the HSC is nothing" lecture. At one point in year 11 a particular girl decided that she had it in for me, and literally tried to make the whole year hate me (I'm actually a really nice person and helped her a lot prior to that, so I'm not sure why). It was only because of my psychologist that I had the courage to tell someone else and put my foot down.
Medicare covers x amount (I've forgotten now) psychologist visits per year if you're referred through a doctor, so I would really advise you to speak to your parents about it and look into it. At the end of the day, they're not going to know exactly how you feel if you don't tell them - at first they may get angry or hurt, but you just have to chip away at them but by bit until you can all reach a state that makes you all happy.
Good luck and feel free to message me if you need anything
P.S. My parents are really amazing people that just wanted the best for me. I was a little shit to them at times, but we call all laugh about the horrors of Net Nanny now