Thanks for your query.Based on the facts that you have posted it appears that you have sustained injury
to your testicle and now getting fluid being discharged from your meatus.
This is not related to the injury at all.It is excessive secretion of a gland in urethra
and nothing to be worried about.as for as long as you do not have urinary symptoms.
As regards pain in stomach it is natural to have pain in stomach whenever you get hit on Testicles .Tis is rffered pain and i not of serious nature.