Thank you all for your answers! There is some really valuable content that you have put together!

First and foremost I am going to make an appointment with an orthopedic specialist.

After that I will consider the fit of my bike. There I've got a little issue. I bought my gravel bike in April when all the gravel bikes at bike shops were sold out because of the pandemic. It was probably quite dumb of me, but I bought a bike online. The frame was probably a bit too big and I solved it by getting a 3cm shorter stem. Now the size feels just right, but practically no professional has seen me ride it. I did go to a bike shop and asked them to check if it fits, but they didn't really check it properly. I mean, I get it, why should they bother if they weren't the ones who had sold it to me? (I did offer them money for this service, but they refused)

What would you do in my situation?