How to stop being afraid to initiate?

I am 26M in a relationship with my girlfriend of many years, and we have hit a roadblock in our relationship where our sex life is almost non-existent. This is because I have such a hard time trying to initiate, as I am very inexperienced in initiating sex and foreplay and when I think about trying it, I ultimately fumble as I overthink about how to do it to a point, sometimes I don't do it at all. I feel like I also lack some confidence, which also hinders my attempts at it, but that's something I am working on separately. I will also say that at the beginning of our relationship, my partner was the primary initiator, but she got tired of doing all the work, so it's about time I put in the work, which I believe is fair and valid, and she isn't in the wrong for it. Do you guys have any advice?