Sorry to see that you're ill. Though quite alarming at first, with luck and proper treatment, it can be a fairly benign illness.
I've had Bell's Palsy. I recall that it lasted about 4-5 weeks, in my case, Prednisone took care of the inflammation as it reduced the swelling in the nerve. Some minor cases even go away in their own after 10 days after the onset. However it's imperative to be cautious about protecting the affected eye with a patch to keep the cornea from irritation
on the non-blinking side.
In the majority of cases, it is a temporary illness with a highly likely prognosis of complete recovery. Think of it as a virus in the nerve (7th cranial verve). This nerve controls one side of the face, eyelid, facial muscles, lips, mouth.
You may have had initially an earache or low-grade fever. I'd been told that cab drivers get it a lot as they're constantly exposed to breezes and a/c blowing on their ear. However, it appears to be a virus or an inflammation affecting that one nerve on one side of the face and head.
Some people are prone to it and have the misfortune of having it revisit them in the future, but the majority get it once and never again. It's important to have it treated soon and it seems prednisone is still the best way to reduce the symptoms while the body rids itself of the virus.
Patching and artificial teardrops in the eye are an essential as the eyelid will not blink and can be subject to irritiation. Also, as you noticed, your lip muscles on one side are in neutral so your smile will be lopsided for a few weeks. Getting lots of rest, as though you had the flu, is a wise idea.
During the time I was afflicted, I also received an additional treatment. I saw a practitioner who used a small medical TENS unit on the affected nerve area. It was programmed to apply some random electrical stimulations which helped the muscles and the nerve to recover 100% and left zero residual symptoms. Here's the link on the TENS device:
My smile muscles and eyelid went back to 100% soon after the illness ended. Depending on the severity of the imflammation, some people are not so lucky and end up with a crooked smile or lazy eyelid. Every now and then even 20 yrs later, one of my eyelids closes a little slowly. That is the only residual effect.
I wish you a speedy and complete recovery.