I'm not sure if I'm having a flare up

So I've been having some weird symptoms for about 5 days now. My legs are weirdly stiff all the time and if I walk for longer than 2 minutes it starts hurting. If I walk for 10 minutes I have to take breaks in between because it's so exhausting and when I'm done it feels like I've walked a marathon. Stairs are also hard. I already called my neurologist in the hospital about it and he said i need to do an MRI and he asked me if I'd be okay with having a stay in the hospital. For various reason I can't do that. I'm also so scared it's a false alarm again and that I'm making a fuss about nothing. Can anyone tell me if you've experienced these symptoms before?