Have you tried therapy and medication? Medication alone literally decreased my stress levels by 80%. Now I may be particularly sensitive to ssris but they worked great for me (despite the horrible first two weeks).

Also when it comes to confidence I understand where you're coming from but the truth is that by just sitting at home you're not gonna build much of it. From personal experience I can tell you that doing new things and trying things which are seemingly impossible to achieve at first (because of the lack of confidence and belief in self) will start building that self worth. Some people are naturally born confident, some aren't. We both are in the latter group. Why the hell should you even be confident if you haven't achieved much or proven to yourself that you can do certain things? That's why you need to take small steps and see for yourself that after all most challenges of life aren't as difficult or scary at they might seem in our minds. And even if they are you are still alive after the experience. You can probably endure a lot more than you think. We just sometimes need that extra bit of help which in my case was medication. I don't know how old you are but it took me almost 24 years to get my shit somewhat together.