Heart problem, anemia, or am i just that out of shape?

Patient: My name is Emily, and im 21 yrs old. Starting about 3 or more weeks ago, i started feeling extremely exhausted (more so than usual, and im pretty sure i have chronic fatigue syndrome though its not been diagnosed.) along with shortness of breath or breathlessness, it felt like a weight was on my chest when i inhaled or exhaled, and it got worse upon moving around even slightly, i could hardly take a shower without feeling like i was gonna pass out i was so wore out.. ive had no appetite really, and i dont use the bathroom a whole lot either.. i was diagnosed with low blood platelets about 3 years ago, but they said i didnt have anemia or thrombocytopenia… but i havent been able to go to doc because i have no insurance.. but i was just wondering if i might be anemic now, or maybe i have a thyroid problem? i am very sedentary, so that probably has alot to do with it.. im jut worried i might have a heart problem.. any thoughts?

Symptoms: shortness of breath, slight dizziness, exhaustion upon exertion, no appetite..