I just don't know

I keep being pulled into this spinning gyre of certainty and uncertainty. I know I am safe with my girlfriend. I know she will hold me down. But, it's the others...all the others that just fill me with such uncertainty. The others tell me I'm not good enough. The others always have something to say that just breaks me down and leaves me confused. And, I know I'm not a bad person. I try my hardest. I give my best. But, I don't like to play with uncertainty. Why would I invest my love and my energy into uncertainty? Why would I put myself in a position that could hurt me?