Mono is nothing to mess with, it can damage your immune system if you don’t get enough rest - and that means not pushing hard AT ALL, physically and emotionally. Refusing to rest, being “a bad patient” will at the very least prolong the period of recovery you require. I didn’t have access to cannabis when I had it (‘71-‘72), but if it’s easily tolerated by your body, I’d use it as I could.
Since I began my career as a heavy head, I’ve gotten sick very little, after a childhood and adolescence in which I was frequently sick with congestive fevers. In a typical year, I’ll get sick once or not at all, aand typically I’ll continue cannabis with no ill or compound effects. This year, the coughing has been horrific, they’ve been too many instances where I feared I would drown in my own phlegm, which has brought me to the brink of fucking combustion entirely.