BB I also left the city where I was born & brought up to live in the market town where DH is from & I can really empathise with you. I had bad bad homesickness for about 16 years & found I could cope by going "home" every so often for a fix! (made it worse that the rest of my family has gradually left my home city so there's no actual "home" to go to).
What finally cured it, as Chandra & Helsbels have said was going back to find so much changed that it wasn't the place I'd grown up in anymore, and the realisation that if I went back it wouldn't be the same. What I was pining for was my old life there, not the actual place.
I left my friends, my family, my work, my social life & my activities (am dram) to move to this grotty horrible place with no facilities (we were without a cinema for 5 years!) stuck on top of the in-laws who wouldn't leave us alone for 5 minutes! I knew no-one at all & was really lonely.
20 years on I still hate this place but DS1 says I know everyone ("how do you know them?!", we rarely see the inlaws (although I'll admit I do resent the fact that DH can nip down & see them in the week whenever he wants, while trying to see my mum involves some major organisation & a 3+ hour drive), & although I wouldn't say I'm actively happy, I'm not UNhappy IYKWIM.
I've found other things to fill the void, including a belated return to the stage, plus mumsnet, so it's not all bad. I don't have an answer for you BB except to hang on in there.