The lashing out stems from a weird combination of vanity and having low self-esteem. They want to get hit on by 10/10 dudes and when they aren't or they are themselves rejected, they lash out at those they feel are inferior to them or they aren't attracted to to feel better about themselves. Psychologically it's called "displacement".
Things like these are of course hurtful to read or hear, especially when it's about physical characteristics you cannot change. The best thing to do however would be to start loving yourself despite any shortcomings you feel you might have. It will build confidence which people don't realize how attractive it is, and also let you shrug off petty insults coming from these insecure women. Besides, as someone already mentioned they are doing you a favour by helping you dodge a bullet as trying to sustain a relationship with people who are chained to their psychological issues is not fun in the long run.
Good luck in your future dating endeavours mate .