First off mate, can I say well done for finding the courage to open up and pour your heart out. Believe me, I've been there myself and I understand how hard it is to actually tell other people that something has gone wrong and you feel as bad as you do. For me, it felt like life was passing me by. I felt like I was a car on the motorway that had broken down whilst all the other cars on the road were driving past me and getting to where-ever it is they were going whilst I was stuck with no way to fix anything.
You've done nothing wrong, this is not your fault and you don't deserve to feel how you do. Tell yourself that and please try to believe it. Depression is an ILLNESS. Nobody gets depression because they deserve it or ask for it, it's an illness that unfortunately ANYONE can be affected by and like all other illnesses it needs to be treated and not ignored.
My advice would be to definitely go to the doctor and tell him/her about it, see your local GP and ask if they can put you on some anti-depressants. Please don't be scared of the idea of being put on them, I promise you they work if you give them time. I didn't want to take them at first because I naively thought they'd mess with my head but the only thing that was messing with my head was my own fears about not giving them a chance. When I eventually did, and I stuck with them, I definitely found that my moods improved. Instead of constantly worrying about my future I found I was able to relax a bit more and I'd guess you'd love to feel that way at the moment. Some people stay on them their whole lives if they feel the need too and there's nothing wrong with that.
Another piece of advice would be to start working out. Do you go the gym? You say you manage your sons football team, maybe try and do some physical exercise rountines with them? Maybe for training one night you could take them all for a run or play some games on a big field? Working out and getting all sweaty is brilliant for a troubled mind, it releases chemicals in your brain that help focus you. I really can't stress enough how much it helps, really. I did it on my GP's advice and I feel loads better, it's the best advice anyone's ever gave me. Since I've started going regular I've lost some weight and gotten a lot fitter and so my confidence has come up.
Please believe me mate, you're not on your own. You have people both here and around you who want to help and listen to you, people who want you to get better and feel at ease again. If you ever want a chat or update on how things are going, please post in here again because I'm sure we'd all love to keep up with you. God bless.