So I've been seeing this guy for about 2 months and he's really sweet and I like him a lot. He's my age (17) and he don't drink or smoke. But I still have a lot of feelings for my ex of almost 2 years. He f**** me over pretty bad but he's saying he's going to change if I give him another chance. He's 19, does drugs like acid and shrooms, he smokes cigarettes and party's all the time. He doesn't even have a place to live! He just stays a crashes at a friends house every night. Idk what I should do. Should I give him another chance?