Sex life..what would you do?

Long story short, my husband and I have been together for 5 years married for almost 2. In the beginning our sex life was awesome. Four years ago, things started to go downhill and he started “acting” like the female in the relationship (no offense to anyone) but there was always an excuse to not have sex. His back was hurting or he was too tired. I’ve brought it up multiple times talking about how it’s important for a relationship but nothing has changed. I don’t think he’s cheating or anything like that but I want him to take things seriously. Even just going to get his testosterone levels checked but he won’t. I’ve done things on my end too..toys, lingerie, different positions, I even lost 40 pounds (thinking maybe it was my appearance) but still nothing. What would you do? I’ve done everything I feel🤷🏼‍♀️ Any advice is welcomed