Excessive lieing is effecting my life.

I'm facing a lot of problems in my personal life. I know I'm lieing but cannot discontinue it. I speak the truth when I write it down. Otherwise 95% of time I am lieing. Due to this I have lost a lot many things in my life. Please help. I haven't told about this to my parents but they know about my lieing habit. & they think I do it with interest. They think I am a bad person because I lie. I am mentally disturbed. I do not speak to anyone now, I have quit socialising, I'm 24*7 with my mobile trying to seek help, I cannot sleep, I cry all the time, I only feel happy & content with my 1 year old neice. I do not feel like talking with my parents, I do not like to stay in same room with anyone I feel suffocated. Suicidal thoughts ad occurred to me almost everyday but I love my parents & cannot do such a thing which will leave them in devastating situation. Everyone thinks I was in very good repo with my friends but that's not true I used to lie to them too. I love to be alone. Please help