Good luck with your goals. I admire you for setting them. I find some intermediate steps and shorter term goals help too. So perhaps setting some milestones around your weight loss goal for example, would help you stick to the plan. Just my two cents.
I swim indoors(when I am not traveling) and the hardest step is that leap from the pool edge into the water. In your case I suspect it's the step from the locker room into the open air. I don't miss 30-40 degree air temperature on deck.
Good of luck with your goals.