Hello risudesu
The upper acromium process is comprised of several functioning pieces including the clavicle.
So the clavicle interacts with the neck muscles, trapezius, deltoid, pectorals and shoulder blade muscles. If all of those interlocking functions are correct we will see a correct clavicle.
Here are some pinterest refs
This is the closest video I could find from Proko.
Congratulations on starting again. Its hard to focus with lots going on and stuff bothering you. Get comfortable and make it something that you enjoy. Its a long road and when you learn to draw anatomy you can learn to draw anything else.
Learn the hard way. Just winging it and covering up and hiding mistakes can only get you so far. No knowledge or not fixing errors in your own work will hinder you in the future.
Try a few more studies and redo your piece.
and post your studies!