Your doctor gave you their opinion and they will be far better qualified than the likes of myself. I have MS and Health Anxiety, I thought I would see if I can offer any reassurance based on my own experiences.
My own experiences of MS have been longer than a few hours. My double vision for example lasted 8 weeks then it got better. I also went numb/tingling and that was a whole leg/part of my side. This didnt last as long but was longer than a couple of days.
Everyones MS is different and someone else might have different experiences, however I thought if you heard what I experienced, then you might realise that they don't sound like yours.
Tingling is a symptom of MS but it is also a symptom of anxiety. MS is uncommon, where as anxiety is very common. One thing that would be interesting to find out is whether you experience these symptoms when you are doing something you love? For example I was worried about a mole and thought it was itching. I found that when I was playing chess, it didn't bother me. I assume that it would bother me all of the time if it was something other than anxiety.
Even if it is MS (Which your doctor has said they don't think it is), most people with MS have happy normal lives. MS can be awful, however as I say most people live perfectly happy lives.
A way I try and think about health anxiety is, that you could get hit by a car. This doesn't stop you crossing the road does it? You don't spend hours looking up car accidents? (If you do then health anxiety is the least of your worries
) Your doctor has given you the all clear, be glad and enjoy life.
Just to mention your point about the MRI, this wouldn't give a diagnosis. They could see any scarring, however healthy people can have this, so they end up having to wait for a couple of relapses before they can confirm. My understanding is that a relapse is anything over 24-48 hours.
Hope this helps.