This all seems to be about his feelings - he loved you for a year, he was devastated when you snogged someone else (when not exclusive), he had to process your 'betrayal', he had to deal with a difficult Xmas, he has to find a way forward...
Any thoughtful, considerate caring person would find the time/'strength' to text you 'happy Xmas - things are tricky here but I'll talk to you later' (or just not mention them at all). Even when I've been stressed/depressed/anxious/struggling I've always been able to text someone I'm supposed to care about back. It's just basic manners, let alone basic empathy.
Have you had a chance to think about what YOU want, how he makes YOU feel, whether this is working for YOU and how HE would need to change for YOU to find a way forward? At the moment it's all about him and all on his terms. You need to explain that it doesn't work like that.
Alternatively you could save yourself the hassle and find someone kind, thoughtful, giving and straightforward.
I've been seeing someone the same length of time and we had our own little 'Christmas', swapped presents, had crackers, ate yummy food. We texted throughout Xmas day. It's not OTT, we haven't said I love you but we have planned trips for next year. Things can be straightforward, lovely and fun if you hold out for the right person, rather than try to fix someone, make things work or fit a square peg in a round hole.
Whatever you decide to do, you need to stick up for yourself and let him know his behaviour isn't acceptable or anything you're going to put up with.