OP, she doesn't look that bad. I'd hit it. You got laid so you took care of your needs. If you feel that bad about it, just don't talk to her ever again.
This....it's just sex. Who cares. I have been in plenty of slumps to where i would do it. Zero ****s given. Do what makes you happy. As long as you arent dating a fatty.....now that is bad. I know some strange guys who have fetishes for fatties too. Cant wrap my head around it. I prefer very petite women with curves in the right places.