Ahh.. Thank God I'm not the only one who has been through this.
Pal, 2 weekend back I kissed 5 girls. And last weekend on a friday I was good but on a Sat I just couldn't open. Didn't feel like and was very tired. You feel like shit the next morning thinking that you have lost your game but no. Going out and talking to people requires you to be in a state of mind, say in a happy state of mind.
But there are days when the week drains you and all you care about it being home and not talking to anyone. Ideas of approacing and multi threading aren't coming as rapidly as they would on any other day.
I go out as alone as much as I do it with friends. And the best way there is start talking to the bouncer, the bar tender get into a talkative mode.
What you are going through is normal. Atleast thats what makes me feel after listening to your story