Somehow or another PT reminds me of learning drums. When you learn drums, you do simple rudiments to get your arms and legs to connect to your brain. Then you apply it to a song. If a song is too fast or a fill is too fast. You slow it down; practice it at a slower pace. When you move up tempo, remember breathing. If a part is too complicated. You break the part into simpler parts and train.
In the same way, even though I cannot do pull-ups, Puah-ups or even sit-ups(used to be my pride) properly now. I training in a way that is very similar.
I am now trying to connect other muscles apart from my biceps so that I can do a pull up because of that, I have been trying to connect my chest and back muscles.
They are still weak so I am doing simple exercises to train those muscles. When I cannot do, I get help and assistance. Try my best and hopefully, soon enough I will be able to do stuff properly.