Some days you are tired, unfocused, busy and you just don’t feel like going to aikido. Sometimes this hides an underlying difficulty you are having with you own aikido development. Sometimes it doesn’t.
Acknowledge to yourself that you have these feelings. They are natural. Don’t berate yourself.
Accept them and let them go. Then go to class any way.
More often than not you end up feeling a hell of a lot better for having made the effort and sometimes you find that these sessions are those when you have an epiphany or moment of clarity that you have been struggling with recently.
Of course if you end up not coming, don’t get upset either. Put that in the past and resolve to go next time you feel this way.