I don’t want to scare you, but I don’t think it is normal, no. You’ve been diagnosed longer than me, so probably have more idea than I do.
Relapses can take many forms, but I don’t think visible swelling anywhere is a usual symptom, and loss of appetite is possible, but unusual. I think you are wise to get it checked out in case it isn’t MS, as sadly, MS does not make us immune to other things. If these symptoms are unprecedented in your eight-year history of MS, I think it’s best not to assume they are related. True, every relapse can be different - even in the same person - so just because it’s not similar to anything you’ve had before doesn’t mean it can’t be MS. But if it doesn’t feel familiar, it would be unwise to assume.
I get a lot of aches and pains, but not everywhere - even during a relapse. I find I get specific problem areas, and yes, walking can be affected, but I don’t tend to find everywhere hurts, all at once, nor that I lose my appetite. I do have an uncommon number of what seem to be stomach bugs these days - perhaps one or two a year, compared to about one in ten years before. So I’m guessing these are connected to MS, rather than being genuine viruses.
But other than that, I’ve not usually had appetite changes.
Have you started any new drugs recently, or checked the patient information leaflet of any drugs you were already on, to see whether these symptoms are listed as a side-effect? What does your MS nurse say, if you have one? Does she think this sounds like a relapse, or is she suspicious of other causes?
I don’t want to tell you it’s normal, because I’m honestly not sure, and I wouldn’t want to put you off having other investigations (if they are recommended), or indeed to tell your family it’s all fine, when I have no way of knowing that. It sounds like you have checked with the medics, which was sensible, but if you are at all concerned it may not be the MS, then please don’t just let it drop. You need answers one way or the other - someone (your neuro?) who will be able to confirm whether this is just a particularly unpleasant relapse, compared to any you’ve had before.
Also have you been ill with anything else (infections?) recently? An infection can cause a sudden dramatic increase in symptoms. Common culprits are respiratory infections (including colds), and water infections.