Depression and ttc

This is my 5 month trying and my depression is getting to me.  I'm starting to overthink everything.  What if I'm not having enough sex?  Maybe I drank too much coffee?  Maybe we having too much sex?  And regret waiting so long to try.  I naively thought getting pregnant was easy.  Now I'm worried since I've spent 8 years using the pullout method and never getting pregnant.  I'm concerned there is a problem.  I just had 3 more friends on Facebook announce their pregnant and I can't help but feel a little envy.  My husband is great but does not  understand my worry.  He says let nature take its course.