@fjdajfkldajkbfejfnsiqn I did a bit more reading in this thread and I'd say this is above Reddit's pay grade, so sorry for any useless or redundant comments.
Some more questions I have:
Have you gone to a physical therapist for this issue?
Are you weak in general or is it particularly bad for your chest?
Are you constantly lethargic?
Have you gained or lost a significant amount of weight post puberty?
Have you ever tried to count your calories and see how much you normally eat? (Ballpark estimate)
Is your lifestyle generally sedentary?
Can you elaborate on your training where you had no improvements after multiple months? E.g. in a week how many times did you train and what did you do?
Have you gotten blood work done to measure stuff like free testosterone?
When you say you have sleep and stress issues, does this mean that you have very little sleep and a lot of stress?
Have you used dumbbells or a machine before to see how much you can press?
Do you feel sore in the days after training?