What could be causing this?

I am 15 and i have had sex a lot of times and we never use a condom and i haven't had sex recently and i know for a fact that i am not pregnant but i cant sleep at night and my stomach hurts and i just keep felling like i have to throw up i don't eat as much and i have lost alot of weight im not really close to my mom so i don't tell her stuff so their is no way i am asking her to take me to the Doctor.. me and my boyfriend broke up so he cant take me to the Doctor so im kindove out of things to do im not hungry and i don't drink alot of water i did get my period and all but i have sharp pains and all and when i wake up i get dizzy and feel like im going to pass out! what could possibly be causing this? and how do i know if i have insomnia?