Need advice from "boy moms"

I need help with helping my almost 2 year old son. He’s very big and heavy for his age, and is strong willed. I am 6 months pregnant so it’s getting really hard to deal with him when he throws tantrums. I also feel like I’m just not connecting with him well and it’s contributing to us bumping heads. He is my first son and his older sister is very petite, and mild mannered so I’m in uncharted territory. Really feeling like I’m not very good at the “boy mom” thing. Any advice on dealing with big, strong, very strong willed toddler boys who can’t quite speak well enough to communicate well yet??? He is also really sweet and a mammas boy, but we are struggling big time lately.