Seems to me that the peat/soil mix is what started the downfall to begin with.

Good luck with your tree.

A trick I learned on another forum is about using a wick from tapla on gardenweb

Take a shoelace or small rope and poke it into the bottom of the pot through the drain hole using a stick or your finger. Put a few inches in the pot and allow 3-4 inches to come out of the hole. If this wick is wet or damp, don't water. If it is dry, then water.

With just the stems and trunk of the tree, there will likely be very little need to water.

To be perfectly honest I regret having repoted the tree into the pine bark/peat moss mix in the first place, because if the tree survives and new growth starts I will have lost about one year of growth, as I bought it in a 15cm (6") diameter pot, and it's again in a 15cm pot due to major root loss, resulting from repotting and repotting into a bark/peat mix, I should've have potted it into the same medium it was in (peat/soil) and wouldn't have had this much trouble, hence now it would be in a 17 cm or even 19 cm diameter pot spreading its roots nicely, instead of getting back into a 15 cm diameter pot with smaller than a fist rootball.
Well what can I say - we learn from our mistakes... From now on I'll make myself a mental note to repot the plants into the same soil they came in from the nursery. I mean if it grows in a soil/peat mix in the nursery, why wouldn't it grow in the same material at home?

Evaldus, I wish you and your tree the best. Most every type of medum works well when they are new. Most problems, if they occur, begin to show up between 6 months to a year. It is at this point that the true value of a medium shows its worth. With proper care, containerized, citrus trees can live for a long time, even for 100+ years. I personally know of one containerized tree that is now 130 years old. Unfortunately, too many reasons to go in to with this particular post, the average life span of a container citrus tree is less than 2 years. Personally, certainly including me, I do not know of a single person that has grown very many container trees, that has not in the beginning lost trees. Again, the best to you and this tree, and a prosperous future with your trees. - Millet (966-)