Patience is going to be your friend. Were talking about 10 years of problems, the solution won’t take 10minutes.
You are doing a lot of great things but some things I would add.
1. Don’t just stretch pecs but work on scalene muscles. They get tight and contribute to the issues you are talking about.
2. Use a lacrosse ball on your pecs, don’t just stretch.
3. Rotator cuff work. This is a big stabilizer and bad posture weakens it.
4. Two pulls to every push for the next 6 months.
5. Lower trap work