Ab workout...

So i haven't done my usual ab workout in quite a few weeks. I have a regimen of about 8 exercises that i do 3 sets of. It was getting easier before i stopped and i wasn't getting sore the next day... And for the past few weeks when i get back from the gym and say to myself "ok quick ab workout, then (insert whatever i need to do)" i never do the workout. I'm not joking this has gone on for about a month... all other exercise has gone great... except the ab workouts. So, i finally got out the mat tonight and went to do my ab workout... got through 1 set, then modified half of the 2nd set, before i couldn't do anymore.... I feel so crappy now. I should have just kept doing these 2-3 times a week like i was... uuuugh. Well, now i have to make sure to do it every 2-3 days so that i can get back to where i was. So disappointing going backwards.... So if anyone out there is putting off their ab workouts.. or any workouts.. go do em now, learn from my mistakes!!