I just got diagnosed with reactivated Mono (EBV positive) and am seeing an ND in Seattle that has had good success with putting patients on a supplement protocol. She says it takes about 2 months but there is a significant difference. Her name is Carolyn Fuller, ND, and she's located at Bastyr University medical clinic in Seattle.
I'm assuming you have been tested for EBV? If so, were your titer amounts tested? A basic EBV test is just going to tell you "yes" or "no" but the titer test will reveal where your antibody ranges are. I had my first titers tested last April or so and they were high. I was just tested again this last week and my numbers actually went up. No real good explanation of that other than my infection is chronic.
Some doctors believe that the high EBV titer values are a secondary cause that your immune system is dysfunctioning from another infection (virus, bacteria, mycoplasma). So you may be dealing with a co-infection, but it's fairly difficult to confirm what that co-infection could be by running normal lab tests through insurance.
Have you had an ultrasound for your spleen? An ultrasound is a simple test and can confirm if your spleen is enlarged. A CT scan is more accurate on the size of the spleen, but the ultrasound is cheaper and no radiation.
My diagnosis so far is chronic EBV and a swollen spleen. I've had numerous medical tests that have all been negative. I also suffer pain in the spleen area that comes and goes, and just like you it's sometimes mild and sometimes uncomfortable. There was a recent stretch where I had trouble sleeping on my left side for about 1-2 weeks, but now the pain has lessened again.
And I also deal with the fatigue/malaise feeling. When all of this first started for me a year ago, I would get waves of malaise across my body. In these last few months, the waves of malaise are confined to my chest area and generally just in the morning. It's a weird feeling.
You may want to consider some alternative medicine. I'm not promoting it as a cure, but if you don't get answers from the medical field, then seeing someone like an acupuncturist may provide some relief. I've gone to an acupuncturist for the first time this month and my last visit left me feeling great for 2 days. I relapsed a little afterwards but not as hard as I have in the past. I think it helps if the acupuncturist is trained in other areas such as herbal remedies and muscle testing.
I think ultimately you need to find a way to jump-start your immune system back into gear. It might take awhile and you'll have to judge what you think is best for your body. I'm all for natural avenues if you can afford it.