I'm 25 and fit. Recently my head feels heavy, tingling on left chest, nausea, can't sleep at all, feel weak, confused, heart pounding hard. Anxiety?

Tingling/ insomnia/ Consider reflux, H pylori which can cause gastritis, thyroid disease, DM, lyme disease, mycoplasma, herpetic condition if a few days. One can only attribute to anxiety if all other medical causes are negative. Follow up with urgent care, doctor.