This is what I was going to suggest....I just finished a scrappy for my dad and had to do this, also.

if you have blocks in the center then - measure your border with the center of the quilt. Make sure both side borders are the same. Then mark down the border piece - say each 12" if that is the size of the blocks. Then pin where the seam in the top should fall on the border. Carefully sew easing in any fabric that has stretched. If you do this by sewing on the border side then the feed dogs should ease in the fullness. It can be done without stay stithing, fusing etc but careful pinning and sewing is the solution when I do it. You can't just cut the borders and sew without carefully preparing each layer.

I have already added 2 sides of the border then quit--do you think I should remove the border and do what Holice has suggested-or leave it alone?

Yep I would take them off, and start over, you'll be happy you did. Remember to measure through the middle of the quilt in three places and take an average, cut you boarder that length and make your quilt fit the boarder. pin PIN PIN, easing the quilt to fit, I think this will work. If you are not sure, just do ONE side and then compare to see if this is the solution. That way you won't have to redo it all to compare

That depends on your tolerance for how it is right now.

I like quilt tops that lay flat - They are so much easier to quilt - and after they are quilted, they are ever so much easier to fold.

I'll give it a try tonight-many thanks!