This is NOT a base or superficial problem. This is very real for you and its adversely affecting your life.

You had a very unfair start in building your self-esteem as a young girl. Your mom was responsible for her own body and had no right to blame you for her problems there. Do you blame your child for your body issues?
And I'm sorry, you may love your father, but he does not sound like a good man. You can't pass blame for what he did to you on to someone else. OMG! Watching porn in front of your daughter?! WTF?! He was a grown man and anyone with a shred of common sense knows how wrong that is. That would warp any girl's self-esteem and body image. The only thing worse would be if he actually physically molested you.
I know what I'm talking about here, personal experience with a very similar childhood. The only memories I have of my own father are of him sexually molesting me and beating my mom. It has seriously messed with my self-esteem and I have struggled with depression my entire life.
I think you need therapy, sweetie. Otherwise you could spend the rest of your life in misery, on this rollercoaster of emotions. It's so much easier to manage when you have help. It might be a good idea to be evaluated for depression, too. Because if you do have it, medication could be a huge benefit for you. It will help you do so much better as a mom, too.
As a side note, I'd like to speak from personal experience again: First, you should definitely strive to be healthy. But, there are plenty of men who love women with a few extra curves. I lost 40 lbs a year ago but I'm still about 80lbs overweight. Even so, since I became a single mom I have had no shortage of dates and I have a steady bf who is very attracted to me. Mmm-kay? It has a lot more to do with how you feel about yourself.
Keep reaching out.