Boyfriend issues

so lately there's been something wrong with my boyfriend, he hasn't been eating as much, losing weight ( he didn't need to or ever feel like he had to before and I've always been loving toward his appearance ) about a week ago he came over and he had an upset stomach so I told him we didn't have to do anything spectacular if he didn't want to, we could just relax, watch movies and cuddle. He was happy the first five minutes and after that he wouldn't kiss me, compliment me, tell me he loves me or show any interest in me at all. He only did while we were having sex which he started I didn't force him to do anything. He basically ignored me the whole time. I expressed how I felt and he brought me flowers an listened to how I felt but today we decided To go to the fair. He "isn't a ride guy" because it makes his stomach sick so all we did was play games, didn't even buy food. he said he felt bad but I reassured him that it was ok. He hasn't been the same happy guy I knew and idk what to do. I'm thinking it's something going on at home or a personal conflict so I'm going to ask him gently about it tomorrow. I just need advice guys