I need advice. How can i help my relationship?

Ive been with my boyfriend for almost 2 years now, hes the most amazing thing to ever happen to me. I wouldn't be who I am now without him. I love him more then anything. Hes been very stressed lately from falling behind in school and an bad housing situation and its really bringing him down. Hes been acting different towards me so i asked him last night if we were okay. He said he just doesn't know. That yes, he still loves me, yes, he still wants to be with me, but he doesn't know whats wrong but it feels different. He told me not to worry about it and that he just needs some time. Well, I cant not worry about it. I feel sick, and I cant sleep. I'm trying to think of ways to rekindle our relationship. I'm terrified of losing him. Anybody have good advice for me?I need advice. How can i help my relationship?
i kinda went through the same thing with my boyfriend. give him a bit of space a day or two and than you two should go for a long walk and talk. go to a park if you can, some place relaxing. let him know you are there for him no matter what and that if he ever wants to talk that your always there. ask him if he would like to do homework together when school starts up again beacuse you dont want him to fall behind. cause it sounds like you care and thats good, let him know. i hope this helps.