名媛直播

Hello to everyone,
I have a question about an indoor Chinese Elm bonsai that I bought in May 2016 in UK.
The bonsai started to lose leaves after about a month and a half, see attached picture

and it lost the last leave around November 2016. The leaves became yellow and dry before falling. In September 2016 the bonsai developed a new couple of branches (still green) at about one third of its height. In November 2016 I checked the roots and cut some of them (following some suggestions found on YouTube), and I added some soil from another plant pot (because some soil was missing, probably due to water erosion during watering). During all this time I pruned the small branches that looked like dry or dead. Until September 2016 I watered the bonsai immersing it in a container full of water, later only using a watering can. I traveled a couple of times in December and March, and I left the bonsai pot for two thirds immersed.
I checked the bonsai today, and it seems to me still alive (the trunk internally is still light green), see attached pictures.




My idea is that the bonsai was overwatered, in particular because I noticed green moss and white mold on the soil and also on the wooden part, and so now roots are not in good shape (rotten), and possibly the soil was not the correct one (I added some from another plant pot) and too much compacted.
Can someone please give some suggestions about how to proceed?
Thank you very much!
ItariaNo名媛直播

Sorry.. Toss it in the bin. It is dead.

There is no such thing as an indoor Chinese Elm. If it had been outside where it should be and lost it's leaves then that would have been what it should do being deciduous, however, inside it will not normally lose leaves. It looks extremely dry. But as Leatherback says it is dead and the pot is not wrth keeping either.

I missed the bit about drowning it.

Looks pretty dead to me.
The submersion of the pot while you were away is not a good idea, I think.
The soil looks very dry and not a good draining bonsai soil.