Hi and welcome,
MS doesn't typically get progressively worse over such a short time frame of a few months, symptoms that spread or travel to both sides of the body in a very short time frame are usually red flags pointing away from neurological conditions like MS. MS literally means many scars so if your MRI's don't have any lesions, conditions like MS are quite low on the list of potential causes...
I totally understand anxiety is often a very sensitive subject but mental health would be one 'potential' explanation 'IF' all the test results are all perfectly normal. When the neurological assessments don't corroborate with the matching clinical abnormalities, the issue 'could be' a sensory perceptional issue, as in neurologically normal but normal sensations are interpreted as being abnormal.
If you tune in and overly focus on these sensation and you experience increasing levels of anxiety and fear, it's possible the worsening is in line with the amount of attention you give these feelings and in line with the escalating fears.....i am 100% not saying that mental health is your answer just that anxiety can cause a rapid escalation of sensory issues with out corroborating objective abnormal test evidence!
"thumb, index finger and middle finger on my right hand numb and tingling" is suggestive of a common type of distal median nerve dysfunction or in other words carpal tunnel syndrome, bilateral carpal tunnel is common and often starts off in the dominant hand first and worse than the non dominant hand.....as far as i'm aware it is suggestive of a peripheral nerve issue eg nerve is inflamed, trapped, or injured by trauma but there are lots of medical conditions that have associated peripheral nerve issues eg diabetes, thyroid conditions, alcoholism, Lyme etc etc
The list would have to be a lot smaller with the addition of facial and oral numbness, off the top of my head both could be caused by hyperventilation syndrome, medical side effects, allergy, there's probably a lot of other possible causes but that's about all i can think of...
Hope that helps.......JJ