Seems to get harder each day.

I'm a new mom,
I was miraculously blessed with a little boy. I've always thought that if I were to ever have a baby that it would have to be a boy. Always wanted a little boy, and I got him. So you'd think I'd love each and every day with him right? Be blessed to have gotten what I had most desired, right? Wrong..
The first few months after his birth were the easiest. He slept all day basically, except for feedings. I was able to breastfeed exclusively which I couldn't have been happier about, the bonding was amazing. The nights obviously were rougher, I expected it to be. But still, I loved it. I loved my new title as a mom, and couldn't wish for anything better. But then when he was around 4/5 months old breastfeeding became difficult, he wouldn't feed for longer then 5 mins, in total!! And was always crying afterward. No matter what help I got nothing changed, I tried everything, herbal medications, pumping around the clock, and was finally prescribed Domperidon to up my milk supply. Which helped a little bit, I was able to breastfeed a lot more again, not exclusively anymore, but I was able to handle the night time feedings, but I started feeling depressed, and disappointed in myself for having failed. Soon it got to the point where even on the medication I couldn't produce enough milk, and recently, after 3 months of trying I've had to completely stop my attempts at breastfeeding. Stopped taking the medication and have gone exclusively to formula and solid foods. I think this has hit me harder then I thought it would, harder then anyone thought it would be actually. It's affecting my mood quite badly, it's affected how I see myself. I had originally planned and hoped to breastfeed straight until he was 1, but I was barely able to make it to 7 months. I shouldn't be so hard on myself, I did try everything, talked to everyone I could. Even with that though, I feel like a failure, and lately I've just been feeling worse and worse about things, and as the months go on my son gets harder and harder to deal with. Sometimes I think that I'm a complete failure as a mother, and absolutely hate the life.
He sleeps through the night now, which we are very fortunate to actually have happening, but the days with him are much harder then before. He wont nap when he's exhausted, after trying everything to calm him sometimes it just doesn't do anything. A lot of the time my patience is tested and I can't stand the sound of him crying any longer. My body tenses up and my head starts pounding and I get frustrated. My mind and body goes into fight or flight mode and I need to release somehow, my body tenses up and I just want to lash out. So I cry, and get scared that maybe one day I wont be able to think straight and hurt myself or my son somehow. I've talked to my mom, told her how I feel and she says it's normal. Any mother who says she doesn't feel like me every now and then is full of shit. Not overly reassuring but she tries. She says there's nothing wrong with me, that I'm just over tired and too hard on myself, which may partially be true, I need to ease up on myself, but even so I'm going to talk to a doctor and get his professional opinion. I don't want to think that motherhood gets harder and more horrible as time goes on, I want to believe that it does get better and easier, and I want to be able to look forward to enjoying each and every day with my family. I think I deserve at least that.