Welcome to the QB and congratulations on your first quilt!! It sounds like you are so close I would just leave it as it is. Trying to even it out at this point may cause more damage that trying to fix it. I recently pulled out my 1st patchwork quilt and I didn't even know to square it up and it is so far off I have to laugh. Be proud of your workmanship. Quilting is 'fun' and there are no quilt police, not here anyway. Again welcome to the QB and the wonderful world of quilting.