Um, I'm no help Bordeaux, I don't have any friends. Seriously. Lots of ppl i know and talk to and relate with, but I wouldn't call them friends.
Kinda don't have time really either, but I guess you could say I have my husband and my sons and Logan and of course life is always busy. Lol.
Did have best friends in Qld whom I miss at times, but 10 years is a long time, so like you I understand everything changes and ppl grow apart anyway.
Are there places you go with the dogs that you meet ppl at all? They would obviously also be dog lovers so at least you would share that in common.
Do you have any mutual friends that you share with your partner at all? (Hmm, not sure i worded that right. Woops.)
Joining the class you are sounds like a way of meeting others, but that doesn't necessarily mean there will anyone there that you click with IYKWIM.
I honestly have always beleived if we can count friends (I mean real true friends) on one hand in our whole lifetime, we are VERY lucky.