Ask.
It's that simple.
You may not like the response or it may surprise you.
The thing is, the more you over think it, the worse YOU make it for yourself.
It's perfectly normal to not like someone and them not like you.
Just get it over with so you can at least work out a way to process it.
Don't EVER be scared of what some one may say to you or about you.
They only matter if you allow them to matter.
Shit, the sooner you realise people just don't matter unless you want them to, the happier you will be.
I would be honest with your friend too.
How am i feeling?
Weak.
I won't be around much, even emails and such.
Just can't focus or do much.
So i'm not ignoring anyone, i'm just taking the time i need.
However long that is.