I agree. Mono only happens if/when you have a very run down immune system. I would get off the steroids and take natural supplements and superfoods to rebuild your immune system. Colostrum is one among many good immune builders.
When I had Mono, my doctor misdiagnosed and kept giving me Antibiotics that I quickly developed allergies to. Since your immune system is whacked out, the side effect you get from meds are very magnified. All meds impact your liver negatively and with mono your liver is probably swollen and in bad shape to start with. Eat a clean diet, maybe juice veggies if you can and take some natural immune building supplements.
Other than that, all you can do is wait it out. I remember I read the entire Lord of the Rings Trilogy with some great background music - that made the experience enjoyable overall even with the pain.