Suicide over possible abuse?

Rite where to start my childhood was very my father walked when And I was bullied because of my weight all through first and middle school we moved to Spain for 2 years and there was no better I was spat on and got heavily into drugs and drink. The real issue here is when I was younger still in da uk me and my male cousin who is two years younger by the way. We used to fool around ually. This happened on and off for about five years. It came to a stop when I was 15 or so I fink. Now it was me who started it and mainly recieved pleasure but I felt the feelin was mutual and was doing nothing wrong. Now 20 he is 18 and am racked with guilt and I know it was wrong what the hell was I doing. I'm a nice guy with a lot of friends and I love my family and would never hurt them . We haven't said anything since and we get on ok but he is now drinking smoking and rebelling. Now I'm ashamed and I hate myself for thinking I may of caused this. To add we are both straight and he has a girlfriend. I don't because I don't think I deserve one. I'm just hope he doesn't get a bit older and fink I abused him. I'm seriously thinking of suicide because of society and my family labelling me as a sicko when I'm not. Also to add to the confusion I'm best mates with his brother my other cousin but I feel like I'm lying to him. I'm depressed and it's all I can fink about please help. Also is dere a chance it will Neva b mentioned again. Thoughts plz thank you.