Here is a picture of the red lady papaya. It is close to one year old.
They start fruiting at an early stage, but of course it will also take its space.
1,5 - 2 metres in diameter should be the minimum when they grow older.
To keep it as an indoor plant it needs a very bright place. And the humidity shouldn't be below 50%.
For the DB, there is probably a problem with the roots. Can you take a picture of the plant, then I can advise you better.
Marcel