upsoearly - I've hesitated about posting, but reading your post resonated with me.
Has this depression and silence got worse lately? There must have been a catalyst to get him to admit he is depressed.
My H was feeling very "down" for about 14 months a couple of years ago. He was also in a massively stressful job that by that time, he hated. His attempts to move away from it and do something else had been thwarted on two occasions in quick succession. So he faced the prospect of staying in the stressful and hated job, with the additional feeling that nowhere else wanted him.
He got worse and worse and started withdrawing from family life. I felt like you - everything in our lives was down to me - and given that I run a business and we have 2 DCs, I was starting to feel really stressed and unhappy.
His behaviour got worse still and he started to lose his temper over ridiculous things - his anger and irritability was disproportionate. I sat him down one night after one dreadful day of this and he finally admitted his depression. I thought we'd turned a corner, just like you. He agreed to see our GP if things didn't improve and thanked me for my support. Once this was out in the open, I mollycoddled him a bit and went out of my way to make him feel loved and supported. I felt really sorry for him.
The anger with everything else remained bad thereafter, although he wasn't being quite so horrible to me.
However, it turned out that although he was indeed very down about work and sliding into a depression, the real reason for the stress, the anger, the withdrawal and the silence was the fact that he was having an affair.
Depressed people are particularly vulnerable to affairs, as are people in stressful jobs that they cannot escape from. I hope that's not the case for you, but I just want you to consider that possibility and recognise the vulnerability.
We have made our marriage stronger in the aftermath, but one of the hardest things to get over was the fact that I was so sympathetic, concerned and helpful - and all the time I was being deceived. This is also the thing that my H is most ashamed of.
He got treatment for his depression through counselling - and he changed his job. The difference in him is amazing.
When I look back to those times when I felt as you do, I cry because I felt so bloody lonely and exhausted. I felt unloved and neglected much as you do and believe me, it cannot go on without you going under too. It's not easy at all living with a depressed person and so look after yourself too.