I was like you for many years Sasha.
Partly I didn't want to let people in, I didn't want to let them see me asking for help...but I also felt I wasn't worthy of asking for that help either. I felt people might like like me as much if I 'bothered' them with my problems.
I found counselling helped me enormously - it helped me not only work through some of those self esteem issues but it gave me someone to talk to and bounce ideas, fears and dreams off of.
That was invaluable for me.