Ok well your first problem is to pay your back maintenance, I would suggest doing a few missions and getting 40-50k.
Once you have 50k in the bank (it has to be in the bank not your inventory) enter the house and you will be given the chance to pay you back maintenance then add whatever you have left to the maintenance pool.
This should be enough to get things running again (as I had the exact same issues this morning).
However if after paying the back maintenance your house is still "abandoned" pack it up and replace it and this should solve that problem as well.
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Charles'M Burns - Structures Trader (Sunrunner)
Montgomery Burns - Weaponsmith (Sunrunner)
Jalek Cizo - Medic/BM (Sunrunner)