I completely understand that! Other then that one, all my other begonias are in a tank because if not they will definitely die 😅 Maybe you can try it that way? Have you tried a Begonia Maculata?
Ok, it could be under watering or even too much light. If you don’t mind me asking what’s the environment? I might be able to help a bit more if I knew 😊 Like is it next too a sunny window, does she droop before you water etc. 😊
Maybe try watering before he wilts 😊 You could also put him in a ceramic pot, it will keep the moisture much longer 😊 I really hope this helps, but definitely keep me updated if you need anymore help 💚