Tunnel vision

I need some medical advise that is not available on my Island of Malta.
I have been diving for two years now 23 dives ( 17hrs dive time ). I am a PADI advanced ocean diver.
During the last 2 dives 15 meters or deeper, 10 mins into the dive I have been feeling a sensation of relaxation followed by `Tunnel Vision ' a sort of loss of clarity and feeling of distance realising thinking that something is wrong I become anxious and think that if I don't abort the dive I will lose consciousness.
This happened first Sept 99,when I had not been diving for 2 months and descended to over 38m, I then planned a normal accent and was O.K. before I even surfaced. The second time this happened again at 35m I rose to 15m and
continued the dive as everything became ok as soon as I reached 15m.
I did not dive until June 2000, first dive 60mins at 10m OK no problems.
Second dive 2000 two weeks later (night dive) descending to 19m I felt the same symptoms so I aborted the dive.
I have asked G.P.s and diving bell doctors, their reply was `It is a `psychological problem' you have to fight it keep diving each time it happens just rise to a higher level and continue the dive.'
I fear that this could be the wrong decision.
Have you heard of anything similar? Are there any specific medical test I could take?

The symptoms you describe sound to me to be nitrogen narcosis which would be more obvious at 35 meters and improve or even disappear following an ascent to a shallower depth.
However I advise you to seek the advice of a diving physician before proceeding further because I can detect an element of anxiety in the case you have presented especially in the last dive you describe. Anxiety will enhance the narcosis.
I am puzzled who the 'diving bell' doctors you spoke to are, there are no diving bells in Malta and the only recompression facility is in St Luke's Hospital run by myself and another doctor.
The advice you say you were given seems incomplete.