no need to quit whinning because you are not. your feelings are very real to you and you have every right to ask for advice.
personally i think a number of things could be the cause of how you are at the moment

1. it could be that you are over worked, over stressed or over tired which is making you want to be alone

2. anxiety could be the cause

3. depression could be too

as could many other things.

you need to talk to a doc or pdoc to get to the root of why you are this way.

you could try being the organiser of meeting with family or bestie, that way you should feel more in control of the situation

you could set time limits on meetings too especially if you arrange them for immediately before an appointment or something so you have to leave at a certain time.

don't be too hard on yourself, everyone has days when they don't want to be around others, some call them 'duvet days', others call them 'me time' or 'hibernation time' but most simply stay home and potter around or watch TV /play on the computer, but whateveryou do the result is the same ...time alone recharging your batteries