Simple thing which matters that much

"You're in a good relationship if you let each other grow and not hold back each other"
"A good friend is the one who let you outgrow yourself without leaving you"
I've been thinking bout those words so much lately. Yeah, lot of things bothered my mind. They're just unfinished thought i had with my self once, and now repeatedly happen in my mind. I guess i'm having an issue with my self. Suddenly i just feel so insecure. I'm starting worrying and doubting that much, which ended badly for me and those people around me.
I know it sounds bad, to let your insecure feeling overwhelm your self and somehow look for excuses to put it on other people. I feel bad and feel sorry. But deep inside down my heart, i feel like i need a space. To outgrow myself bigger than i already am. I happened to be someone who is looking for something to be achieved. I'm a seeker for opportunities. I love it when i should get my self out from comfort zone just to see if i could survive. But what I'm doing these days are those which are the opposite of things i had in mind. It is the thing which make me feel unfulfilled. Those simple things which drive me nuts, forced me to look for things i left once. Those good old days which gave me satisfaction trough things that maybe people couldnt see and barely care about. Do you ever being in this phase? I do now, and it sucks to realize that you cant really count on anyone but yourself. Cause you're the one who is responsible for your own happiness, you cant put the blame on the other. I'am 19 going 20, and it really is my responsibilty about what is going to happen in my life. I make my own, cause the other will not stay there forever.