So horny and starting to feel lonely!

Okay, so my husband and I used to have a good sex life. It was fun but ruled by his likes and dislikes. He can be a bit vanilla, he can be a bit inexperienced. Mostly, because he doesn't want to take the time to try to explore. For year's I've asked to try new positions, games dressing up/roleplay, sharing our bed (I'm bi), and exploring our sexuality but no. So in recent years, he's gained weight (won't eat well, consistently) and we can't have sex. I went off my IUD last year b4 covid in hopes of him getting a vasectomy but everything shut down and it's been a mess. We have had sex and I get the plan b but during those times he can't perform. He looses interest or we have to stick to 2 positions in order for him to keep up for a while. I like to be on top but that's been unachievable for a while, even b4 this past year. Lately, I feel like I'm desperate for intimacy. I want to be held and loved up but it's not happening, I know its crazy but I feel like asking for a girlfriend or something. Ive never cheated or want too, I want him but I just keep feeling like I need more. I keep hearing myself say, maybe he'll let me get a good night in with a dude and then I feel horrible and sick for thinking it. I would never ask or want too but I feel confused! I feel frustrated that he seems to be bored or put off by sex at this point because I've tried to find what interest him. I've tried to get him to explore himself more but he refused and now he's given up? Idk!