New relationship - problems.

Anon for obvious reasons.

TLDR: New girlfriend, very happy, great foreplay but actual sex isn't going great, bothering both of us. How to improve? Thoughts?

So me and my girlfriend have been together for a couple of months, and whilst we've had a few hiccups along the way we work really well together and make each other very happy. However, the biggest snag so far has been the sex. We have great foreplay, but the actual sex itself just doesn't seem to be going well - obviously I know that since its bothering both of us, we're probably overthinking the problem which is making it worse.

I've never encountered this in a relationship before, sex has always just been good (unless I've been lied to consistently for several years ) - its never been something I've had to worry about before.

Theres a couple of things I can think of thats a problem - first of all we're both under a lot of pressure at the moment from various things, and our routines are a bit out of flunter at the moment so we're both going to bed late together, tired etc.

I suppose what I'm looking for is some reassurance that things will improve, or if anyone has any advice on how to help it improve that'd be much appreciated.