Ocrevus first dose side effects/Digestion issues

Had my first Ocrevus dose last Wednesday, I had a reaction half way through - skin rash, ear/scalp tingling, slight breathing issues. I was given Hydrocortisone and extra piriton then IV was restarted. Due my second dose on 4 Sept. I have been floored with fatigue since, more frequent bathroom visits, slight cough and digestive issues like gastrtis. I have had issues tolerating steroid infusions before and had digestive issues and they affect my mood, which I told my nurses about but I wasn't prescribed anything to prevent this. I am taking Nexium since Weds. Anyone else have similar experiences, of so what did you do? I am thinking about taking a probiotic but read you shouldn't take lactobacillus on Ocrevus. Any advice/shared experiences are appreciated. Thanks 😊