There isn't a reason to keep trying rows with 65lbs (or any exercise with more weight) if your form was bad. You should always warm-up with just the bar anyway at this point, so I'd say feel your way into it, see when form starts to break down and start from there. Especially starting back up, you will make more progress doing a bit lighter weight with proper form than trying to push it and developing bad motor patterns.

The first few weeks of doing something, you're going to progress more out of general adaptation than muscle gain, anyway. (As learned from physio recently, it actually takes 6-8 weeks for strength to actually increase significantly. The rest of the early improvements is only your mind/muscle connection getting better)

Start low, what u think is low start lower. I was off training for about 2 years from injury to my abdominals & left hip. Slow and steady core work did me wonders and now I can lift more than I believed I’d ever to get to again