OP you have done amazingly well. I know lots of us beat ourselves up lots of the time but honestly, to drop almost half your body mass after surgery, AND then regain only 15 - 20lbs three years later, AND to have had a baby in the meantime is unbelievable.
Third year regain is common - the norm actually. Trying to get back to your lowest weight ever might not work if your body has chosen a higher new set weight. It will fight you all the way. Forever.
Please cut yourself some slack. It might be helpful to ask yourself what exactly you're aiming for now. Is it a goal weight/BMI? Or a state of mind where you accept and celebrate the huge changes you have made to your health and your life and now that of your baby. If you have a set goal, why is that better than where you are, and how much effort or angst do you want/need to devote to achieving it?
As a general observation processed and ultra processed foods (products with ingredients you don't have in your kitchen) are what make people obese. The sooner you can ditch those the better IMO. Freshly prepared food is less likely to cause regain. I am a big fan of Dr Matthew Wiener's book A Pound of Cure. Might be worth a read!