As Carolina says, vitamin D3 is important for MSers. Some people say it’s helped with their fatigue. I haven’t noticed a difference, but we’re all different. It would be worth having your B12 levels tested too. A lot of MSers are deficient and low B12 levels can result in fatigue, and neurological symptoms.
I take a multivitamin too, but tbh, that’s because my diet is rubbish! If you eat a healthy diet, you shouldn’t need one.
Fish oils are supposed to be really good too - so eating lots of fresh tuna, mackeral, etc (oily fish) is good for MSers.
If you have MS fatigue, then you could ask your GP or MS nurse for amantadine. It is approved for MS fatigue. It doesn’t work for everyone, but is definitely worth a try. Another med that a lot of us are on for fatigue is modafinil. It’s not actually approved for MS, but a lot of neuros and MS nurses prescribe it. Unfortunately PCTs are clamping down on it being prescribed for MS, so you may not be able to get it. It’s worth asking though.
An abscess is bound to make you feel rubbish. I hope you get better soon