Help!! Any med students out there??

So recently I’ve began losing weight, feeling lightheaded upon standing, having loss of appetite, feeling fatigued, and having a slight fever/ sweating. I’ve been losing weight for quite a while now even when I wasn’t having a loss of appetite and not going to the gym as regularly. In fact, it seemed as though I became skinnier when I WASN’T going to the gym. I’m already skinny as it is so getting even skinnier is not only worrying me, but worrying my boyfriend and some have asked if I’m anorexic. Honestly, it sounds like this thing called Addison’s Disease but it’s super rare and I’m unsure if it affects my age group (i’m 17). Has this happened to anyone?? The weight loss has been going on for about 2/3 weeks now and all the other symptoms a few days.