Sometimes, families say things without realizing how hurtful they can be. Maybe you could mention to them how their comments affect you. I'm sure the last thing they want is for you to think they don't care. Don't let their comments get to you! You are doing this for you and you only. Angeleyez said it best!

Doesn't matter if the whole world says you are fat, if you don't want to be, then you know what to do.
20 pounds is a great achievement. As far as your clothes go, perhaps they were tight to start with, so while they are not falling off just yet, maybe you're just wearing the right size now and they fit "better". Am I making sense?
I used to feel the same way as you. I wanted to be thin NOW! And ironically enough, I wanted to be thin so badly...and was so far FROM being thin, that I just didn't bother trying or I would give up early on because it clearly "wasn't" working (that's what I decided anyway).
Others are right, you have to keep going. So many people give up after losing some weight because the road ahead just seems so long, but I found that once you get over that hump, it becomes more of a second nature to eat better and exercise.
I find it really helps to stop focussing on "wanting to be thin" and switch your thinking to "I want to be healthy". Makes eating right and exercising easier. The pounds and inches will come off as a nice bonus to being healthy!
Hang in there. Hugs to you

and a rolling pin for the family
