I hope I haven´t found this post too late and that you have decided to stay!
Please, don´t follow through. Any problems you might have had or any mistakes you might have done during the course of your life, are not worth the attention and importance you would be giving them by ending your life. Even when it is impossible to see, life can get better and you can change it to make it better!
I really hope after writing your post you have decided to seek professional help! But please, please stay!
I myself at different stages of my life was very close to ending it, but I am so glad I didn´t. I am so glad I didn´t miss what my life has become now!