Fat slap

I know this is gonna sound gross but because I have such a low hanging stomach and excess skin/fat on my upper arms I'm embarrassed to go to a gym.

I walk everyday around my neighborhood but I know that going to a gym is the next step. And, yes I know I could exercise at home but the gym has all the strength equipment that I could never afford.

But when I do exercises like jumping jacks, step aerobics, etc my fat slaps against my legs and side.

Anyone else ever had this problem? And still joined a gym? And how did it go?