You're on the right track focusing on gluts. You will need to add in quadriceps, there is a video I made on youtube for this here:
Click Physiotherapy - knee extension exercise - YouTube

There is a great manual technique that could help to relieve some of your symptoms, I'm in the process of editting that video so subsribe to the youtube channel and that should be out very soon.

Other than these the main thing will be load management. Here is an article that should help with this:
What your rehabilitation is missing.. - Click Physiotherapy

I hope these help! All the best with this and let me know if the exercises help. If it does get worse, make sure you see someone!

Kind regards,