I feel defeated

My son is almost 3. Recently (6 weeks ago) I had another baby. When I was pregnant his behavior was all over the place but it seems like since there’s a new baby around it’s gotten progressively worse. I can understand if he’s desiring more attention or is adjusting to change. But I feel burnt out and frustrated because nothing is working. We’ve tried time outs, sticking to our boundaries, even a swat on the hand or butt, amongst other things. Unfortunately he’s hitting/kicking, throwing, screaming, biting and pulling hair. I used to be able to guide his behavior by talking to him or putting him in time out for 1-2 minutes to help him calm down. Genuinely nothing is working. He’s about to be three, so I’m also wondering if it’s just him becoming a three year old or if he’s wanting attention.