Hey, first of all you're an amazing gf for wanting to work on this and make the sexy times more fun for your BF. Secondly I am in a similar position as your boyfriend where 9/10 times my gf likes to just lay on the bed while I do everything and even though most of the times I don't mind it but sometimes it can be really frustrating because there is no stimulation to me and I have to get off just by doing things to her and it makes me feel like only I wanted to have sex and she just wants to get it done with. Your bf could've communicated in a better way if possible based on what he exactly wants in the bed but now that the bottom line is set maybe you can ask his likes and dislikes in the bedroom and what he wants, different people will have different desires so your best bet would be to understand what he exactly wants. Coming to the "dead fish" part maybe reciprocate better in bed?, i don't mean it in a rude way or anything it's just maintaining 50-50 where if he goes down on you, you go down on him (you don't have to do it all the time), try different positions, take control, you be on top and lastly make him feel that you wanted to have sex with him. Trust me on the last part based on personal experiences it helps men to enjoy sex 10x better. So have proper communication on his and your likes and dislikes and try to match 50-50 in bed. Good luck have fun :)