sometimes I want to put my fist through a wall

I love my son so much and he's such a happy little boy (5mos) but when he throws a tantrum... god, the screaming and kicking. I have bruises on my knees from kicked in the same place and I try to hold him in my lap. I feel horrible but I just have to put him down and walk out of the room before I literally punch the wall. I would never ever hit him or hurt him but sometimes I just want to scream back at him and I have to stop myself from doing it. I love being a stay-at-home mom but some days I just want to crawl out of my skin and run. is anyone else ever feel like this... does it make me a terrible mother?? my husband is wonderful. He tells me to just bring him to his office. if I feel like this once every blue moon I wouldn't feel so bad but if I feel like that once a week is that horrible???