My advice is to get a really good physical therapist. It seams to me that you like me have some kind of slap tear but it's not that bad.
My doctor said physical therapy won't work. I am not yet 100 %. But my physical therapist believe I will become. And so do I.
I go twice a week and get new, more difficult excercices each time.
It depends on your person whether the mri will help. Your physical therapist will probably be able to help you even if you don't do one. For me the mri was a nightmare, and what the doctor had to say about the outcome even worse... Now I have slowly regained confidence. To me it's not so important to know exactly what is wrong. It is more important to keep believing that I can and will improve. But this imight be different for you.
I also think that you do need to slow down I bit, make sure you don't push it if you feel that it's not good for your shoulder. You look quite strong

So I'm sure you will be able to build up enough mussles to keep your shoulder healthy!
Accourding to the mri my shoulder is really quite a mess. But thanks to me taking it a bit easy and physical therapy it is really getting a lot better. Even if my doctor adviced that the only think that might really fix it is surgery. (Take not of the might.. it might only get a lot worse...)
Take care!