Is it realistic or pessimistic to realize that you can't rely on anyone in this world except yourself? Are you setting yourself up for loneliness? Or making yourself more open to relationships with other people, seeing as now you know what to expect. I suppose it's a matter of perspective. You can either feel weaker because you know you can't depend on others. Or you can develop a greater sense of self-worth and strength relying on yourself and challenging all of your vices and idiosyncracies. And you know that if for some reason you do fail, you tried your hardest (or you didn't) and you know exactly how to remedy the situation, and are aware of all the surrounding circumstances, because we all know, you can't lie to yourself. You are your own worst enemy/critic.
In the end though, I suppose you're just trying to convince yourself you don't need anyone, and you're still just pissed off at all the ones who let you down.
Bollicks.