Hello. I am having serious HIV scares.I am currently a nursing student. I had sex with a guy a four years ago?

however, he pulled out the condom out without my knowledge. Now, I am having HIV scares. I am most scared of getting tested. Above all, I feel like I have toxoplasmosis. I have been having this sharp migrating headaches since aug last year. I also had an allergic rash in aug 2009. I am really scared and above all, i am feel like i am developing other symptoms. Are there other ways i can take care of my health without doing an hiv test?How do i cope with that and school? do i have to tell my school?