Hi well come to HCM.
It seems there must be lot of collection of smegma
which might have given rise
to phymosis with swelling[oedema]. So keep good hygenic care,roll back for skin of
the penis gently and remove yellowish material below it[smegma].You can wash or
clean with warm water even and after that apply some antiseptic ointmentment
. It should go if not show it to your Doctor. Thanks