Driving Myself Crazy

OK I really need to unload abt something that my sane side is telling my insame side that I'm really getting worked up over nothing. I'm a member of our local chapter for the Canadian Celiac Association.  I'm responsible for contacting the company that advertise in our newsletter, collecting the ads & forwarding accordingly for print. I took over this task abt 6 months ago now.  It was difficult at 1st because I was sent so much info & e-mails on so much fr a few diff people that my head felt like it was swimming sometimes. The last person that did this task sent me a listing of the companys, e-mail addresses, contacts etc. So the 1st time I did the job a few of the e-mails did not transmit successfully.  I was frantically trying to figure what the $(%*^*& was going on, staying on time, etc. etc.  I finally did find out that a few of the e-mail addresses she had given me were incorrect (letters missing and/or transposed). So over the last few days it was time to start the procedure over for our next newsletter.  I've slowly worked on refining/streamlining the job & got the requests for ad sent out.  I got a reply back fr a party, I won't go into detail, stating that there was no Pat & Mel Dietrich at that address & don't e-mail again!  I thought Hello, I'm the Pat & Mel Dietrich(me & hubby) sending & clarified the TO party.  I was very professional & asked that if there was some error or whatever going on to advise me & I would promptly look into the matter.  It bothered me SO MUCH AFTER & I could not leave it alone that I researched back into the past trouble with e-mail addresses that were given to me.  Well I did find one more error.  So right away I made the adjustments to my e-mail address for the company I deal with & now have the right one on file.  I double checked and triple checked. I was so pissed off with myself I sent the upset party a nice e-mail stating that the matter was corrected & sincerely apologized, etc. etc. BUT, why am I letting this bother me so much.  A simple clerical error was made along the way here but I feel like I can't forgive myself, want to kick myself fr here to eternity.  Sure don't need this stress hanging over my head. So if anyone wants to either tell me I'm crazy or try to sort me out, I love you for it.