How can I get my natural crease back, after I've constantly used double eyelid tape ? (tape was self cut, not constant or exact)

Unfortunately each and every time you peel the tape off of the eyelid, you traumatize the eyelid and can cause the loose areolar tissue in the eyelid that hold the tendon of the eyelid in place to give a little.  Stop taping, it the natural crease does not come back in the next two months, it is likely you will need a double fold surgery to restore this.

Use of double eyelid tape on the eyelids does not provide a long term solution to change the natural anatomy of the eyelids. Chronic manipulation of the lids by placing or removing the tape, unnecessary hand-to-eye contact, rubbing of the eyelids, and sleeping in the prone position potentially destroy the delicate tissue layers in the eyelid. For the next several months, giving the eyelids a rest from the tape and any other manipulation or rubbing, would give you the best chance for recovery of your natural creases. You may have inflammation and mild swelling from the chronic taping and tugging on the lids. If the natural creases do not return, then the crease and the lid level could be restored by surgery. An Oculoplastic Surgeon experienced with delicate and precise eyelid procedures could give you advice based on your current examination and measurements. Your youthful eyelids might recover in time if left alone or treated gently, but a consultation might be reassuring to you. Best wishes.