can you reassure me or am i wrong?

[worried.me]

i have not been happy in my job for a while and have managed to secure an interview for a position more suited to me.

I had an interview 2 weeks ago and as a result they said i was over qualified for that position but wanted to interview me for a different position. The person doing the interview was on holiday was away last week so i could not arrange to go on my day off. So i am going to have to call in sick as i cant get any day off this week. I feel so bad doing that and had nightmares about it last night but dont seem to have much choice now.

[nightmare]

It is highly unlikely your current employer will be able to ascertain the date of an interview. For all they know, you could have been offered the job on the basis of the first interview.
"Pull a sicky" and go for it.
I was in exactly this situation last November. I was successful and now am in the best job I have ever had, by a massive margin.
Incidentally, my new employer did not ask for a reference from my previous employer, but from the one before that, which I left in 1997 !