No matter what struggle you're going through, resist the urge to feel self-pity. Every time you dwell on and feel bad about what you're going through, you push yourself deeper into the abyss of despair. You might not be able to control the mental issues afflicting your mind or the hardships you're facing but you can control whether you feel sorry for yourself or not. Self-pity is the voice that tells you that you will never be able to overcome and the thing that precents you from ever trying to.

There was a difficult phase in my life before I went to college. Life was hard because of school pressure and other things. It made me depressed and self-pity was how I dealt with it. Years after, I realised that the thing that I was using to cope with my hardships was the thing that was not only making everything worse but creating more problems for me.
If you're a Christian remember that self-pity is the opposite of trusting God.