Hard Core Parenting

This post is unplanned with no pictures or anything else exciting...just me ranting...so feel free to skip over.
I'm sure my mother told me growing up a million times(and I know she has told me since I have been an adult and a mother) but parenting is so hard. A million decisions, constantly questioning if you did the right thing or if you just screwed up your child for life. And for some unexplained reason, I was certain that if I just did everything "right" than parenting would be so wonderful and problems would be limited.
OK so reality sets in. God sent me Dallin. Today I am not sure if this is a blessing in my life or in his. What am I doing? How did I possibly think I could raise a child? And even if I was capable...THIS CHILD?! Come on! I have never felt so inadequate in my entire life. I am constantly able to rattle off about a billion mistakes I make in a day (and not just the stupid things like...what laundry detergent would make his clothes the brightest and whitest? but things I think maybe he'd be better off if he had a shot with a better mom) At this point I am not sure if his behavior or mine is the problem. If I wasn't so lazy...If I was cleaner...If I was better organized....If I was more consistent....If I interacted with him....If I didn't yell...If my discipline was more appropriate...if if if if...would he be a better kid?
Tonight, I went to gymnastics. This is his third week and he is always so excited to go. I knew he was tired today...we just got back from California and he started sharing his room...which means no sleeping and LOTS of partying..and bugging Kate by throwing toys into her crib and climbing in himself for a jump jump while she is asleep. But off we went to gymnastics. I got my neighbors to watch Kate and everything. After 10 minutes of gymnastics class, being treated like Dallin had the plague by the mom of the little girl he adores (it was like she couldn't stand Dallin being around her daughter), 2 wildly unsuccessful timeouts, and a head on collision with a little girl (the same one with the annoyed mom) after he wouldn't slow down and quit running around we went home. I am at the end of my rope here...I am trying to get Dallin around some other kids who are well behaved, but, of course, they don't want their kids around him for fear his behavior will rub off. I get that, but that is what we are HOPING for ....the good stuff rubbing off. I put Dallin straight to bed when we got home.
I was so humiliated and angry and upset. He is so wild and so defiant and he's 2...he can also be sweet and adorable. So I feel like I have created this monster and now I don't know what to do with it. I am feeling really overwhelmed by all of the changes to be made and I am not sure I am able to do it all. I'm not the patient mom or the consistent mom or the nice mom or the fun mom or the clean mom or anything.
Parenting is hard core....praying for a better tomorrow and some divine intervention.