hi there -
congratulations on getting back in the pool!
I don't have any suggestions except to commiserate and share my plan with you...
I'm in a similar situation - first time back in over 2 decades, about 30 lbs heavier than when I last swam competitively, and a little disappointed with my times this year.
I have seen my endurance improve somewhat over the past 9 months after working out about 3 times per week, and so my longer events (200 and up) have seen time improvements (20 sec), but my shorter events (50/100) have not been dramatic (about 1 and 3 seconds, respectively).
My plan for the 2013 short course season is to seriously work on dropping some weight (goal of 3-5 lbs per month) and to add some dry land training to improve strength. I'm hoping that the combination will help improve my times.
Also, I've been told that it can take up to 2 years to really get back in the swing of things after an extended absence, so don't lose hope yet!