How to Bring my Eyelid's Elasticity Back?

Lower eyelid tone is dependent on the function of the orbicularis muscle, tarsal plate, and the condition of the lateral canthus.  It sounds like you may have disruption of the lateral canthal tendon and may be a candidate for surgical repositioning of the lateral canthus.

Hi Stan,
Reading your concern, I am fairly sure that you have not accurately describe what is going on. I certainly could guess, but I am not sure how helpful that would be for you.
It is unclear if you are describing upper eyelid ptosis with one of the upper eyelids lower than the other. This can be seen following head trauma. These are specialized reconstructive eyelid problems that are best addressed by an eyelid specialist.
As you are in Canada, I recommend that you see a general ophthalmologist or your regular doctor and get a referral to an eyelid specialist. This may be a problem that is covered by your health insurance.

The elasticity of the skin is directly related to the aging process. Genetics, sun exposure, and smoking are the primary drivers for aging. The elasticity of the eyelid skin has nothing to do with banging your head against the wall hard several years ago. If there is enough elasticity of the upper eyelids, a blepharoplasty can be performed.

There are so many reasons why you can have eyelid asymmetry after an injury.  it can be related to scar tissue, to nerve injury, to normal asymmetry, to facial fracture, etc..  You should be evaluated by a plastic surgeon, ENT, oculoplastic, or even an oral and maxillofacial surgeon.

A photograph would be very helpful. It is possible that your injury divided a facial nerve. Specifically the frontal branch. This nerve controls the frontalis muscle. If there has been a weakening or total denervation of the muscle then your eyebrow and consequently your upper eyelid will droop. At this point you require an evaluation by an plastic surgeon. It is possible that reconstructive surgery may help to correct your problem.