You need to be honest with him about how you feel. I wonder if there is some compromise you can come to that may help you feel more at ease? Do you have anyone who could come and stay for 'holiday' with you whilst he is away? Or like pp has mentioned book in some extra care and help for the time he is away?
I would worry that missing such an acknowledgement would be seen as a negative from his work's POV as well as being something he should celebrate ITMS.