Sex doesn’t feel as good as it used to

For the title it’s obvious what this is about. Since I got my iud my sex drive has plummeted and overall made sex not feel as good (because now it takes me a lot longer to get to a point where I want to have sex and am ready to). I dont know how to tell my bf honestly because I know he is really sensitive about it. My birth control is the problem and I don’t know how I can improve my situation. Any suggestions?