feeling like a horrible mother...

I don't know why but lately I have been feeling really horrible I feel like I just can't do it anymore it's so hard taking care of a baby could it be because my SO never helps me out? I feel like a bad mother for not being able to enjoy my 4 month old but I just feel so depressed and upset my SO never helps me out and will have him for like 15 minutes and give me any excuse for me to have him again.. on top of that he goes out to run errands or whatever and never want to take the baby with him. Am I horrible for wanting him to take him? He makes me feel like I'm not a good mother and says the baby should always be with me. But I feel like it shouldn't be that way.. on top of that sometimes I get so frustrated I love my baby but I don't have patience with him sometimes I just want him to be a year old already.. am I horrible for this?