I feel that there is calculus formation between your cap and gums because of which the gums have been pushed down. Because of constant irritation from the calculus there would be inflammation of gums. The gums would have become red and swollen and also it would bleed when you brush and floss. You need to visit dentist
at the earliest and get the area cleaned (by scaling). Get a radiograph (X ray
) done so that any changes in the tissues (especially bone) beneath the cap can be seen. If necessary get a new cap done.
Take care and wish you a speedy recovery