Memantine for VM?

So after Effexor stopped working I have been prescribed Memantine. Coming off the low dose of Effexor has been harder than I expected -- I feel terrible 24/7 last two weeks -- or maybe this is just how I feel now but am supposed to take a week off before titrating up to 20mg of Memantine. Just curious if others have been on it and how they did. Only found a post from two years ago...