Meacarpal Damage

Hi, around 8 months ago i broke my 4th and 5th metacarpal by punching a door.
i had surgery , (although in a Eastern European hospital).
i now have 3 metal plates and several screws holding my hand inplace from my knuckles to my wrist.
before i was a keen boxer but since my injury i havent felt the same and often feel weak (due to my hand) . ive had enough of feeling like this and also would like to take my boxing career back up . i still have the metal in my hand but is incredibly painful when i lightly try to box the bag , any suggestions how to get back on the horse ...?? much appreciated!