Bananas.org - Dwarf Namwah with BSV??

Hello!
I bought a dwarf namwah last spring, and it was growing quite well until I noticed that its anchor to the soil in its pot was a little bit poor, and at the same time, a chlorotic leaf came out.
I decided to water less frequently, just in case I was overwatering, because the soil in the pot is the typical soil mixture for containers, which I then read here that it retains to much moisture... And together with the leaves I thought that it might be a phosphorus deficit combined with to much watering.
And so I went to the store and bought an organic liquid fertilizer that was rich in P and N. This was around mid October.
I live in Madrid, central Spain, and it can get cold (subzero in fall-winter - not a banana climate). Actually October is a kind of a mad month, and all sort of weather changes can happen over here. The fact is, it was rainy for a few weeks and quite chilly, so I don´t know if the the cool weather prevented my ``remedies´´ to work. Actually, the naner slowed down its growth considerably with the chilling, but still, two leafs came out but they where still chlorotic.
And then I started suspecting about the dreaded banana streak virus... Being my first banana plant, its quite off putting, really...
I suspect that a canna lilly they gave to my father is to blame.
I was intending to plant it in a home I have in southern Spain, which is much much warmer (something like zone 10) but know I´m doubting if to plant it or not. Maybe when spring comes it will grow vigorously enough to overrun the virus? If a find another source for dwarf namwah, I would pull it out, and put the new one, and see, and in the mean time I can see if a get some bananas from this one. Or is it just not worth it?
The place I bought it from has good references in the forum, but maybe their mother plant got contaminated or something. Nothing against them if that is what happened, cause I think that can happen to a serious nursery at times, and their service was very good. But it is a problem to find another source for DN here in Europe. In any case, I don´t really know it its BSV (lets hope not!), and if it came contaminated, or it got the virus from the canna lilies.
And know, the photos!

This is the plant. The older leaves look more solid green and darker.

This is the first chlorotic leaf that came out.

And this is the second leaf that came out. Its got a small deformity, which I don´t know if it might be virus, or some mishap due to cold coming in while developing.

Thanks to all of you!!