I’m 5 months out and am also powerlifting, which I was doing before surgery. I think going back to cardio is a good idea. Also you can add protein to your diet without eating meat. Try dairy, oats, legumes...
My problem right now is keeping muscle. As soon as I make some gains my body gobbles up the muscle. I can’t take in enough protein from any source. Also, I noticed long plateaus and slow weight loss. I attribute it to the powerlifting which is why I think the cardio is so important.