Don't take this the wrong way, but your behavior is indicative of mental health problems. Worse, depending on the underlying cause and if left unchecked, this could develop into some serious mental health issues like schizophrenia.
Obviously, there's little to go on (and, obviously, IANA
LP), but the "i got so paranoid, i recently cut off all of the contacts" is the troubling part. A close friend of mine exhibited some similar "need to go off the grid" behavior, and it caused some very major disruptions in his life and downstream problems.
The good news is, this isn't a huge deal (now) and can be easily remedied. There are plenty of treatments avaiable and, chances are, it's not anything major. It could just be an anxiety disorder caused by the stress of a startup, in which case the occasional dose of diazepam will bring you back to normal.
But either way, you need to get it checked out. If you have health insurance, you're probably covered, and if not, a few visits won't cost too much.
And separate bit of advice on a shrink: see someone who can perscribe meds (i.e. a psychiatrist instead of a psychologist)... I'm a fan of pharmaceuticals and think they can treat mental health issues better than therapy, and psychologists might be biased to think otherwise. I have some serious anxiety issues with the dentist, and given the choice of long sessions or Zanax, I chose the latter. Works wonders!