I am so afraid

I am so afraid that there could be someone else in my hubands life.  I cannot shake this feeling.  I have absolutely no proof what-so-ever and I have a very overactive imagination so am I conjuring up things to fit my thoughts or are they really there.  There seems to be a plausable explanation for almost everything but then I can turn it into a full-fledge affair too.  I'm driving myself nuts.   I am consumed by this.  I want a definate answer and I may already have it but I'm not satisfied with it.  The answer that I know right now is NO he's not having an affair so why am I so consumed all of a sudden with the possibility that there is someone else.  Is it because everyone has filled my head with this thought so now I think it must be true.  You know the "power of suggestion".  Our mind is such a powerful tool and can manipulate us in ways we are not even aware of.  I don't want to hear people say "oh, yes he must be having an affair, why else would he leave".  There really are lots of reasons and yes that could be one of them, but up until now, for the last 5 months I have never thought it was.  Now all of sudden I can't get the thought out of my mind.  Like I said I'm driving myself nuts.  If there is another woman in his life, even after he left, than I know my marriage is over and I'm so afraid of that.  I've been trying to hold onto this marriage, trying to save it, trying to give him time to see the what an idiot he's been until he comes back home.  This is all I want in life right now.  So the idea that there could be another woman scares the shit out of me.  But once again, I have absolutely no proof at all.   I need positive reinforcement that some marriages just end because of mid-life crisis.  He wants time and space and no worries.  It doesn't always have to include another woman even though some attorney's state thats always the case.  It very well might NOT be the case this time.   I know a lot of you on this web-site have been burned by the OW, but that doesn't mean everyone has been, right.  I need some positive thoughts here from the DS group.  Please don't speculate like I am - I can do that all on my own.