You are absolutely welcome, my friend.
You know, a couple of things really stick out for me here.
One, even in just a few lines of text you come across as a nice guy. In the real world, that counts.
Ok, mebbe a bit anti-social…no, you know what? I don´t think you ARE anti-social, I think you are mebbe not meeting the right people.
Got any hobbies? Find an evening class, meet like minded people. Take the Mrs with you. She might like to be a diesel fitter 
Walk down the road with a smile on your face, say Good Morning to the postman, Have a bit of craic with the old lady behind the counter at the Post Office. Compliment the cafe owner on the coffee, It´ll work wonders with your outlook on life, trust me. Meet life head on with a cheeky smile on your face.
I was in a band when I was in me 30s, lead guitar. Everyone said “Why do you look so miserable when you´re playing”?
I didn´t know I was, I was just concentrating on the song I´d spent 40 hours learning!
ANyway, that hit home. I then concentrated on playing with a smile, looking at the audience, meeting their eyes.
WOW! What a difference! Within a week or two I was tripping over new friends and, more importantly, groupies
. I was a lonely, miserable effer once. Not saying you are. though.
Two, you already KNOW why you´re having problems and are trying to address it. Whether this is going to be physically changing jobs, or mentally trying to cope with your problems on the job you have, I´m 100% convinced that you will find a way through.
Smile, be confident, think positive, and ■■■■ em all 
Good luck brother, let us know how you are getting on.