I feel I am not progressing.

This is such a common feeling. Here are some reasons.

Not enough practice. Easy answer play more.

Ineffective practice. Not working through problem areas in detail. Lack of focus, ie practicing too many things at once. Playing pieces that are too hard.

Expecting too much. Unrealistic timeline. It can take years to master things.

Self-criticism. A little is helpful. Too much will mean every note will sound wrong. Play don't criticise. Adapt the here and now.

The plateau. You have reached a certain level and it seems hard to get any higher. Think sideways. Play pieces at a similar level but a different style. Swap speed metal for funk. Blues for Motown.