5'4 and postpartum

Hey everyone! I am recently postpartum. My son was born in August and I need to get back into working out. Prior to getting pregnant I was fairly active at the gym, lifting weights and doing cardio at least 3x a week. Once I found out I was pregnant I didn't even do cardio. I was on the couch 24/7, and I gained over 70 lbs. I started at 220 (pregnancy weight) and I'm currently at 197. I have a wfh job and I sit pretty much all day & am always exhausted as I get up in the middle of the night with the baby to feed him etc. What can I do, that is simple enough for weight loss & building a better body image again.

TLDR: recently postpartum. Baby is almost 5 months old. Went whole pregnancy without cardio or working out and i need to get back into it to get back to normal weight. Looking for recs on how to do it without being so exhausted

Pre pregnancy and postpartum pics included