It's not that you suck (I think these are great shots, btw), its just that as photographers, there's always more to learn, we can always be better, and there are always others out there better than us....especially when looking at the work of people here. As such, we perpetually think we suck, but its a matter of perspective.
Humans are hardwired with a negativity bias, and its our natural tendency to get discouraged when you're not where you want to be in terms of skill....don't take the desire to be better as a reason to quit, rather, see it as an opportunity to grow and get better, and use that as encouragement to practice and improve your technique. As photographers, we will never improve (and our skill levels will stagnate) if we fail to recognize areas where we can be sharpen our skills...The fact that you recognize areas where your technique is lacking is actually the first step to elevating your skill level.