not much if im honest, if only bc im not sure what to do.
- go to a counsellor
- talk to your doctor
- read some books regarding mental health?
- exercise (it's proven to help improve mental health, though by itself it won't fix things)
Being as honest (with yourself and others) and genuine as you can be also helps (because it helps you know who you are, as a person).
Finding your principles in life (and testing them for consistency) and living by them helps, because it helps you get to know who you are, as a person.
Identifying what character traits you admire in other people (it's the easiest way to identify what you admire), and seeing which of those you have in your life, and working to improve and strengthen such traits within yourself helps - because you now know you have traits you admire, and no one can ever take that away from you (particularly if you work on them)
You have within your reach many resources to assist you in improving your mental health.