Hello Irina!
I am sorry to hear about your problem but as I happened to see you live in Romania, I might know someone who can help you out and your little tree. A month and a half ago I have discovered this splendid website
www.atelierbonsai.ro/ . The owner, named Sabin, is a very knowledgeable man in the field of bonsai and he's helped me repot my Podocarpus Macrophyllus with great results of back budding and new sprouts in only two weeks. I believe it is worth trying to contact him and tell him about the issues of your Fukien tea, maybe he will be able to help you out in this matter. If you happen to live in Bucharest, that's even better news !