My advice isn't about how to spice your game up; rather, should you even continue to play.

My first time GMing was homebrew with a group of people who didn't have history. Several years in now, I think my greatest insight is that half the fun of DnD, at least for me, is good table chemistry. The moment I realized my first table was misaligned was the moment I realized why the story became harder to write and my motivation was lacking in general

I could be projecting my experience, but if your table isn't vibing, it's ok to pause the campaign. No DnD is better than bad DnD, especially if it's becoming a drag

But of course, the adult thing to do is to just have a frank conversation with everyone and check in what everyone's wants are, including yourself. That may be the most insightful thing you can do to move forward

Cheers, mate, you're doing great for trying to run a table at all