Why am i so insecure about my body

Im 18f and i hav grown up around ppl who always comment on my body (not food comments) like im so thin and i should eat more, i used to love my body because i don't want to be fat but because of so many commnets I've come to feel like am i really looking that bad? Because of this i am not able to be comfortable around my boyfriend what if he also does not like me? I am not ready to be naked infront of him I always wear baggy clothes outside so i don't feel conscious what to do