Discomfort on left side

I was having the classic mono symptoms for about a week an a half and my doctor agreed after blood test that it WAS EPV and my mono cells or what-not were doubled[20%] which meant I was fighting it off. but when I started getting better something else was happening. over time my left side felt like it had grown it definitely feels efferent then the other side of my body. I figured it's the whole deal with the spleen being enlarged, It is uncomfortable and aggravating because I don't feel like I get enough breath like I used to. My whole upper left side, including my arm is just uncomfortable and doesn't feel good when I use it. Is this normal and how long does it take to go down and what should I be doing. Thanks so much for anything you can provide.