Some walls are for climbing and some are for walking around. Stubborn isn’t the same as strong.

Persistence is only a virtue when it is aimed at something that will move. Plenty of obstacles are not tests of character at all, just features of the situation, and pushing at them spends the strength you will need elsewhere. Working out which kind you are facing takes honesty rather than grit. Strength includes the judgement about where to spend it.

Name the thing you keep running into and ask what has changed in the last month of trying. If nothing has, look for the route around: a different class, a different person to ask, a different order of doing things.