I too know those feelings very well. At times, I really wished I wasn't born because I make the wrong choices constantly especially the big, life-altering ones. I feel like such a waste because my brothers, for the most part, have their lives together and have succeeded at their life choices but not me. When we get together, like for holidays, they all talk about one success or another and I just kind of slip away so I don't have to talk about myself.
BUT, the point is, everyone messes up at one time or another. EVERYONE. Your most important choice is whether you concentrate on the failures or the successes. What did Edison say? Something like, "I didn't fail five hundred times at inventing the lightbulb. I succeeded at finding five hundred ways that didn't work." You can see there are a lot of people on this website. You can either say there are a lot of messed up idiots on this site that aren't good at life or you can say there are a lot of nice but confused people who just need some help dealing with life.