Ultimately all the advice in the world leads to one simple starting point: You have to act, practice, and rehearse new skills to get their benefit and those first acts, as with any new skill, will be clumsy, embarrassing, and full of other challenges that will lead the novice to feel bad.
If you try, you will fail and feel bad, worse than if you never tried, but if you stick with it, you can overcome the failures. You’ll never lose access to the skills you now have it you don’t want to feel or act social, but you can when you want.
The reward for overcoming those failures, in my experience at least, is so much greater than the struggle to reach that reward, that I only wish I had started learning social and emotional skills earlier.
I created my courses to make the process as easy as possible. The glowing testimonials tell me they work with a lot of people, though they take time and effort.