Pain in upper back. Look somewhere else?

I have a persistent pain in upper right side of my back. The pain is not severe and it doesn't make me uncomfortable as such but has been persistent since last 8 months. Initially, I visited a physiotherapist and she asked me to go for home remedy like hot water pad etc. I used that and pain was reduced a bit. But it was not completely gone. I somehow lived with it for past 7-8 months. But in last 3-4 days the pain has increased. I visited the same physiotherapist and she has started the treatment (like radiation therapy etc) however the pain seems to be still there though it has reduced a bit. I searched about it on Google and few articles suggest that such persistent pain is symptom of a very serious disease. I'm really worried now. Shall I discontinue the treatment of physiotherapist and look somewhere else? If yes, which doctor Shall I approach. Kindly help.