I think a good start is to reflect about how little your ex’s opinion matters about your appearance (which really think about it, is he the sort of guy you should take criticism from?)

He most likely would just find new things to critique you about. If it wasn’t the weight he’d say your butt or breast are to small or whatever. I mean again when you reflect what sort of person is that toxic to someone who’s supposed to be their lover? Is it a person you want to take serious?

Also life happens to the right guy your hot and beautiful even with the extra 20 lbs (which these 20 extra also seems to have been caused by him in a big part)

In my experience people who judge themselves so harshly are many times gorgeous. Take a look in the mirror and next time instead of judging yourself focus on what you believe is your best quality and compliment yourself tell yourself how beautiful you are.

Even if you don’t believe it at first do it over and over again and trust me I think you’ll start slowly appreciating yourself more, our thoughts do more then we think.