bugs406 on "Need help-going crazy"

5 weeks ago, I bought a used couch from a thrift store. Brought it home and googled how to replace a couch cushion. Immediately sites about bed bugs came up and I began to panic. I learned how to search for them and spent hours tearing the couch apart. I found nothing....no fecal spots, no cast skins, no bugs. I was so freaked out, however, that I got rid of the couch 4 days later. Since then, I have put encasements on both mattress and box spring (both of which are 3 months old). I put climb ups under the metal bed frame legs. I bought bed bug blue and tested every little black thing I ever saw. I have a few "bites" but they aren't welts and they don't itch at all. They could very well just be little pimples.
I am obsessed and can spend hours searching my bed with a flashlight. I check my sheets every day and occasionally find very tiny black flakes which lift right off and don't smear when wet. I have bought a new comforter and isolated my bed away from the wall. I am obsessed with checking my body for any possible bite mark...its ridiculous. I know this isn't rational but that doesn't seem to matter.
I am so stressed and overwhelmed worrying that I might have bed bugs...it is seriously hurting my life. I don't want people to come over-just in case. If I had bed bugs now ( after 5 weeks) what kind of signs should I be seeing? How can I let this go?
Thanks for your help!