Hi there,
I'm sorry that you're going through this.
I was never diagnosed with MS, but I was being "watched" for it as my first brain MRI showed white matter lesions. However, a follow-up MRI months later was unchanged, and my LP was negative. So I sort of had the opposite test results. But only a few of my lesions were "MS-like," most were "non-specific." Lyme can cause brain lesions as well, that may or may not look like MS lesions.
From my understanding, which is by no means a replacement for a true medical opinion, Lyme can cause optic neuritis. I have no idea if ON is more often from Lyme or MS. I do know that confirmed ON increases your chances of developing MS in the future.
A big difference between Lyme and MS has to do with the distribution of symptoms. In Lyme, bilateral (or approximately so) symptoms are more common, while in MS, the symptoms are caused by damage to certain areas of the central nervous system. That means the symptoms show up in particular places and it's very unlikely to initially be even on both sides of your body. So having the same symptoms in both feet is an unusual (though not impossible) presentation of MS, since it would mean that a very symmetrical lesion had formed.
Lyme patients may not commonly have ON, but we do often have symptoms involving the eyes, and again, both eyes are usually affected. Bilateral ON is extremely rare in MS, and eye problems usually present in one eye and not the other. My eye problems include pain upon movement, flashing lights (like cameras going off) when I move my eyes(very obvious in the dark), floaters, and mild double vision (sort of like "1.5" vision, there is overlap between the images). None of these problems could be explained by an opthamologist, nor did I have any lesions visible on my optic nerve in my MRI.
You don't list these problems, but for the sake of discussion, MS does not cause joint problems or rashes, both of which are more common in Lyme. Also, symptoms that move around a lot are unlikely in MS.
There are lots of theories about links between Lyme and auto-immunity, and Lyme-induced MS. The cause of MS is not known, and some think that certain cases may be triggered by Lyme. But I don't think anyone is really sure.
If you have any concerns about a Lyme infection, you should be cautious about the treatment of your MS. Are you being treated with a DMD? I don't know much about them or how they affect the immune system, but you should keep the thought in mind. Also, MS flares are often treated with steroids. Steroids suppress the immune system, which is appropriate for treating auto-immunity but terrible if you have an underlying infection like Lyme! They may make you feel better at first (more energy, less inflammation) but if you have an infection, steroids will in the long run exacerbate your infection, causing it to worsen considerable. Again, I know just about zero regarding the MS DMD's, but I think copaxone is a better choice if you may also have Lyme. Follow up on the topic as you see fit, but don't take my word for it.
There is an MS forum here on MedHelp and they may be able to offer you advice as well. The community leader is a retired physician who has MS herself. Here's a link to it:
http://www.medhelp.org/forums/Multiple-Sclerosis/show/41
Lyme patients know all about incompetent doctors, as many of us go years undiagnosed. I myself was told over and over that I didn't/couldn't have it and nearly lost my mind while in diagnostic "Limbo."
Take care.