You’re legally required to tell the DVLA, so you must tell them immediately. There’s a medical questionnaire you’ll need to fill out for them, then several months later (and that’s not an exaggeration - they really can take months) they’ll probably issue you with a 3 year licence which you need to renew every 3 years.
You also need to tell your insurance company straight away too, as failureto do so could invalidate your insurance. There’s been several threads on the boards about whether or not you need to tell them or just the DVLA, with different people adamant either way. But it’s always better to be safe than sorry - running the risk of invalidating your insurance isn’t worth it. However, my understanding is that they cannot increase your premium as a result of MS.
Hope that helps. You should tell DVLA. Have just been phoning round for quotes as my car insurance is up for renewal. Some companies do ask the question about medical conditions whilst others do not. I have another medical condition apart from m.s. and whilst this is notifiable to the DVLA some insurance companies don’t want to know about it. Don’t assume becasue it’s on a list of notifiable conditions for DVLA it is also on a list of notifiable conditions for some Insurance companies.