In the same boat here. Most people my age have already graduated, and I'm not even a senior yet. I'm taking two courses in the fall and I'm still worried how I'll do. I've had incompletes multiple times. Longest I had one was four or five months. I've failed several courses as well. Flunked out of my first year of college.

I have a good friend that's older than me and has been in university several years longer than I have.

I agree with jenniy: don't let the guilt eat away at you and try your best. It might be taking you longer than most, but there's nothing wrong with that.