It's summer, and my parents are always aggravating me about..?

going to the pool. I don't like going to the pool because I think I'm fat. I'm 14, and I weigh like 144 poundss. I have a few stretch marks on my sides and I've been puttin stuff on them and stuff to make them go away. ( or, get lighter.) I am about 5'3''. How can I get them to stop aggravating me? Or, how can I go to the pool without getting embarrased.