Bad mom

I am feeling like such a horrible mom right now. My 3 year old has been acting out a lot and I have been exhausted. The amount of boundary pushing and the attitude/screaming is out of control. I utilize time out and I try to talk to him about it after. Bedtime is the worst because I am so tired (falling asleep on the couch) and he is refusing to go to bed even though I know he is tired (probably the cause of his attitude). I end up having to put him in his room and walk away so I don’t explode. I feel like I already can’t deal with one child much less two. 15 weeks right now and I work full time. My husband works nights so he is asleep most of the day. I’m at a loss for how I am going to do this.