I got circumsised already but there seems to be like a flap or extra skin still left hanging. when i get an erection it shortens. is it normal?

See my remark: If there are skin flaps hanging and if they are attached to the head of the penis they tend to retract the shaft. It is hard to ascertain the condition by e-mail.If you can afford it see a urologist This can be remedied...cheer up !

Circumcision: it is normal for the skin to shorten with an erection if it is a flap of foreskin left. You could have this checked by your doctor and if it really bothers you it could be surgically removed by a urologist or plastic surgeon.