Sweetbriar, There is no ryme or reason to his madness right now...try not to over analyze his every move or comment.
If you don't feel like responding back today, maybe sometime over the week you could respond and just say "I'm okay" and leave it at that. Nothing says you are ready your text messages at this time.
I certainly wouldn't acknowledge the anniversary. I would do something nice for myself that day.
For now, just let all of your messages go to voice mail or leave them in the inbox. Tomorrow is another day and who knows what it will bring. I do hope you will feel better soon.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.