How can I reverse this extra eyelid crease?

Eyelids open and close many times during the day.  This causes long term changes in the eyelid.  It is likely that the new crease you are seeing is related to this.  Will it go away?  Not necessarily.  If you have had eyelid swelling, itching, or irritation, then perhaps.  It the issue does not go away, can it be remedied without surgery? Without at least a photo or ideally an examination, it is hard to know.  If this does not resolve in the next month, it is much more likely to be a new persistent feature of the eyelid.

Impossible question to answer without examination. It could be from slight change in eyelid position (such as ptosis) or from more fat loss or other cause. See an oculoplastic specialist.The treatment depends on the cause.

Eyelid creases can form over time due to descent of the eyebrow or with aging due to increased skin elasticity. An eyelid lift or blepharoplasty can improve these creases. Occasionally, laser skin resurfacing also helps.