If it were me? I'd tell them all to GO FUCK THEMSELVES. You might want to be a little more mature than me though, and just turn the other cheek.
I'd be willing to bet 85%+ of people commenting on your weight haven't cosplayed, and most of them are way less attractive. I can see your photos, and they're nothing but a bunch of jealous bitches that you got an interview and they didn't.
Momma always said "SOME people can't live without carping" and it ain't worth it to let it get under your skin. Maybe tape a video response to the interview telling the haters where to stick it is what I say. You look great.
Look at that shit. That shit is adorbs. Haters gonna hate.
I've been where you're at. I did a photoshoot with an ex that ended up on a "Wall of Shame" site because it was a personal, private shoot and I didn't bother with makeup or some of my accessories. Got ripped apart by 4channers. It was over within weeks but it sucked while it lasted.
Just remember this too will pass. And if you need to rant, hit me up on PMs.