Tibetan Massage, what exaclty does it do?

Even though I have received my officially recognized Tibetan Massage certificate, I am not entirely sure yet when to use Tibetan massage on people and what it does. My teacher has taught me how to do the massage but I don't know too much about it. His teachings were very practical. There was a huge language barrier so he didn't explain a lot beyond the actual technique. Every time, I tried to ask about it in a more theoretical way he was unable to answer my questions. At some point, I decided to give up and just do the research myself in order to answer my questions. Now, since I know how to do the massage I just have to learn the theory myself and I am good to go.

I haven't done lots of research but here are some basics that I have gathered about Tibetan massage: Tibetan massage is a particular technique that can help many physical and psychological problems whether they are caused by humoral disturbances or daily stressful works. In Tibetan massage, specific acupressure points, meridians as well as therapeutic herbal oils are used to open up particular channels in the body to increase energy flow and vitality. The goal of the massage is to make energetic channels clear and open from stagnation. If the energy is not able to flow, it ultimately leads to blocks and difficulty controlling the mind, which then result in psychological and physical problems. If one is free of blocks and stagnant energy; naturally the flow of ones life-force increases, the mind is clearer and emotions are more stable.

Knowing all of this is very interesting but it does not entirely resonate with what I have learned. I have been taught a particular technique that is used on back, arms, legs, chest and head. I am also aware where the pressure points and meridians are but what I don't know is which meridians or pressure points are responsible for depression for example or anxiety. Do you have to vary the way you massage according to the individual person. How do you decide where to focus on, how do you know what to focus on in connection to the problems the person has?  

Many questions but no answers... Anyway, at least now I have some questions. Although I won't find all the answers I have opened up a field of interest that I might want to follow up on in the future.