Sometimes it’s something like a UTI (urinary tract infection) that can make your legs do things like that. So perhaps take a urine sample with you to the doctors and get it checked out?
Unless as Poll suggested it’s foot drop (where your toes won’t pick up when your brain gives the command). In which case, try to get some physiotherapy. In fact, you should do that regardless of foot drop.
Or it could be the start of a relapse. Do you have any new symptoms, or has anything got worse lately (apart from your legs giving way that is!)? If you have new symptoms, speak to your MS nurse asap. S/he should be able to recommend some steroids and get onto your GP to arrange a prescription. I am assuming you are RR not SP or PP (relapsing remitting rather than secondary or primary progressive).
Sorry if I’m explaining too much, but as you said you are newly diagnosed, I’m assuming you are still in the ‘big learning curve’ stage of MS.
People are such gits, supposing you to be drunk. I presume it’s because you don’t look ‘ill’ or ‘disabled’, and are young and male. This is where a t-shirt saying ‘I’m not drunk I have MS’ would come in handy. Regardless of that, keep in mind that it does happen to us all at some point, either the falling over, wetting ourselves or worse. The last time I fell over, I was using a crutch at a cafe in the summer a few years ago. My husband dropped me off right by the cafe and went to park as it was rammed. I walked up a small path towards an empty table with bench seats either side. I went to sit down, was a bit too close to the edge, fell off and landed on my bum. Two complete strangers did at least come and help me up. It’s a benefit of being both female and a bit older (I assume) as well as having a crutch!! Still horribly embarrassing.
But, see what your doctor says, are you seeing your GP or neurologist? I ask because many GPs are not ever so knowledgeable about MS, which is why it’s worth talking to an MS nurse or neurology nurse. If needed, they can liaise with your GP as well as physio and any other services near to you. Plus they could see if a neurologist appointment is available soon. My area has a community neurology team, which is multi disciplinary, so most services are either part of the team or they can refer you to other services that they don’t cover. So I can just phone them and ask for some physio help for instance. So maybe see what is available in your area.