Hi and welcome,
You might want to look into trying an orthotic solution for your foot drop, a brace called an ankle-foot orthosis can help keep your toe-foot from dropping eg walkaid, footup, but there a lots of different types and it's better to get a physiotherapist to work out which type will best suit your situation.
A physiotherapist would also help you too but there are also some really great online exercise programs specifically for MSers now that are free eg themsgym I've heard some MSers are very happy with their improved mobility issues...
If your walking stick isn't providing you enough stability now you might want to consider trying a walking frame, arm crutches, knee walker and for longer walking trips to preserve energy use a scooter, segway, manual or powered wheelchair
Hope that give you some ideas......JJ