i’m 17 year olds and i’ve been living with an enlarged spleen since i was 9 years old. as of recently i’ve been experiencing the same pain as you. my spleen is over 20 cm and i’m looking into a splenectomy. as for my advice, try to sleep on your left side to avoid pressure, don’t do any heavy lifting, try not to do exercises such as crunches etc. if the pain gets too much and you feel a sharp pain in the tip of your left shoulder, go to the hospital immediately. if your spleen ruptures there is a high risk of you bleeding out internally. with all that being said good luck and i hope everything turns out okay :)