I only collect Byzantine coins, but your could be either Byzantine, Latin Empire of Constantinople, Bulgarian or perhaps from a Balkan land close to Byzantine Empire. I have one of Manuel Komnenos, Byzantine emperor from 1143-1180: Obverse side: Jesus sitting Reverse side: Manuel Komnenos in left blessing by Mary in right. But giving the style and flan of your coin I am somehow convinced it is outside Byzantine Empire, maybe Bulgarian, but the timeline would be from around 1100-1400. In ancient forum section they may help you better.