Hi there,
Sorry to hear about your problems. There is always a solution to such issues. I would advise you to see your GP sooner rather than later.
I have advised some student friends of mine in the past who had similar issues to ask their doctors for certain types of medication, and tbh, while people do have concerns about side effects and other problems, the right medication in the correct dose at the right time for a short spell can work wonders.
From what you say you are going through esp. about your physique, the insomnia and loss of interest in hobbies/socializing, etc. you might well have an early stage anxiety/depression type of condition as you say, and if so, it responds very well to treatment, in fact surprisingly so!
SO, TO REITERATE, SEEK MEDICAL HELP STRAIGHT AWAY!
Best wishes!
M [former medic]