Help?!?!?

So I’m not that sexually experienced, I’m not young I’m in my late 20’s. Well I’ve been dating this guy for like 8 months. We have fun and the sex has always been great. Well I feel like we are at this weird crossroads and it’s effecting me sexual. It’s coming close to the “what do we want out of this” conversation so I think that’s playing a part in it. The last few weeks I feel like sex has been different. Before we could have sex 3 times in a night and he would last a good while. Well lately I’ve been cumming first. It’s like I get mine and it still takes him a while and at that point I’m like why hasn’t he cum yet. We’ve gone for a long time and both have enjoyed it. Honestly it’s just my insecurities kicking in and I wonder if he’s enjoying the sex. I know it’s good that he last longer and he’s been trying new positions lately. Which I think is good and is suppose to happen?? With me not being that experienced I’m just worried that I’m not good enough. It’s not every night that I wonder. Some nights were great and the sex is great. I know a lot has to do with the confusion I have about our relationship but any tips on how to help with the insecurities? Do those ever go away?