British Masters extra post!

Spent the last three days in Sheffield at the British Masters Long Course. Should be a guide to how my improved training regime and loss of weight is letting me swim faster (or not). In summary the Championships were very successful for Gloucester Masters and me with one or two provisions. My 100 and 200 times are getting faster which is great news, but I am still struggling to get any more speed over 50metres sprints. I have come to the conclusion that I need to change my technique to improve my 'catch and pull' through the water. Overall everyone from Gloucester had at least one medal. I managed two silver and a bronze with two 4th's. In addition I was part of the 4x200 freestyle relay (200+) which won with a new British Record. My fitness is improving but not as fast as I would like. I did manage to swim a 200 free followed by a 200 IM within 30 minutes this morning which for a swimmer who last year would only manage two events in one session if at least one was a 50 and the other a 50 or at best a 100m. In terms of comparison to this time last year my sprints are similar speeds. My 100's about 1-2 secs faster and 200's 5-6 secs faster. Looking forward to a summer of training and improvements through to the Nationals in October. Then will be a better comparison of how well I am doing. My problem is identifying which changes in my life are helping the most, weight, training, change of diet, type of training, stroke technique and so on. Next target stroke technique. Any suggestions let me know please..