i need ur help

hi there,
My name is Adham and I’m in turkey right now, I’m living here from 3 years for my high education, sorry for my English it’s not so well but I need help with my relationship :(

ok.... firstly i have a girlfriend from 3 years we r together, really i love her so much and i cant live without her, she got the same feelings towards me and we decided that we will get engaged late this summer, but the problem is that i had another girlfriend and i didnt tell her about this matter, and i swear from 2 years i cant sleep because im thinking so much what ill do:(how i'll tell her about my other girlfriend, I know it's my mistake and i should honestly tell her but im afraid to lose her. so what should i do? wait till the engagement time and tell her or from now?

the second issue that im thinking about my future with her soo much, really this make me sick bcz i cant sleep i can’t eat, only thinking how i'll live with her, what we will do? Does the family will accept me or not? Where we will live? really my brain is 24/7 working in this 2 matters, i need help here what should i do to stop thinking about all this stuff, and it's still in the future, but i cant make a dissection this is the problem.
Please reply back as soon as possible with the best solutions that really can help me, or medical solutions, I can’t sleep i think so much :( sometimes I sit and cry because I cant stop thinking about this 2 issues, I cant stop what should I do?

thank you,
Adham AL-Alami