Yes, you have to make friends with yourself and you do that the same way you meet/make friends with anyone, you talk to them, get to know them, and, with yourself, don't judge (because it's you; you're doing your best for yourself as that's all there is in your world; you can't control anyone else, you can only give over your own control to others).

I asked friends I trusted (primarily my husband) what they liked about me, why they were friends with me and they told me about my sense of humor, my ability to understand various things/people/situations (my perspective?), my honesty (actually, that's one thing I like) and I like my creativity, imagination, and learned to like my whackyness/sense of whimsy/"mistakes".

Practice spending time alone and you will get better at knowing you and relying on you; it is much harder when others are around. I did a lot of novel reading and paid attention to characters I like and what that said about me. I thought about subjects I liked in school and why (what I might have inherited from my ancestors, like my love of history) and looked at aptitudes I have (I'm a good "navigator"/don't get lost/can follow directions), have a good memory, etc. I just took stock of myself over time and then looked for the good stuff and learned from the mistakes/harder stuff I didn't quite like.

Make it your job/goal/project/interest to get to know yourself.