I don't know what to do anymore......

Here is the thing.... My husband doesn't want to have sex with me. We're supposed to TTC but after 4 months of trying he is not into sex anymore. We don't have sex since January, we are still young. We don't have kids. I've asked him what's wrong but he said that he doesn't feel like having sex and he doesn't know why. Can someone give me some tips on how to seduce him in bed ? I've tried many things but I don't see results. I know he come tired from work but on his days off he doesn't want intimity with me. Sorry that I have to come here for tips I don't know what else to do because he is not giving me a good reason....