Welcome to this site. Inconsistent stitches. I have been to hand quilting classes with 4 top British ladies the message from them was keep going and not worry. The size of the stitches not important but try to be consistent it will get easier. They all hand quilt in different ways so try different styles. In a hoop, try with it tight so thimble bounces off to a bit slacker no bounce, not floppy. Try holding in your hand no hoop try borrowing a floor stand again watch tension of piece. A tip I had was to do blocks to join for quilt as you go. These blocks I promise you get better as you go. Also technique straight needle down and thimble or some pusher on hand below. I use those round sticky things on more than one finger. I also try to have a long nail on left hand first finger and use the nail to push up. Keep practising and have fun donot stress.