Hi Michael, Since you are only a week into it, don't worry about the future. Everything will fall into place. For many people they feel so good eating vegan that they never turn back. Dairy is definitely the culprit for a lot of negative health conditions, as it sounds like you have discovered, so as you feel better you will likely be so glad that you took that first step.
As far as the leather, some people are so disconnected, in fact most people are disconnected from the reality of what leather really is (yes they know it comes from an animal intellectually, but somehow are able to disassociate with that reality). After being vegan for awhile you may find yourself becoming repulsed by it, because you really "get" what it is... but if not, you can still wear it without contributing to the suffering of future animals. You can maintain what you already own, and/or you can buy used/vintage items.
When buying new, you tell the industry that the item is in demand, thus contributing to the deaths of future animals, but this is not the case with pre-owned/used/or vintage items. And some of the faux leathers today are hard to discern from the real thing. I realize that biking apparel probably would not hold up if it were not real leather, and probably wouldn't be warm enough either, but I know nothing about biking. There must be other people in your situation, so you should see how they handle this, or if there are some other clothing options.
As far as the refrigerated trailer, you are financially commited to this. I'm sure that there are refrigerated vegan items that need hauling, but seeking them out may not be practical. You have 2 more years to think about and weigh all of your options, and within that time frame you will likely be able to resolve your ethical dilemna and find a solution that works for your life.
I recommend heading over to facebook. There is a large vegan community there and you should be able to find support and friends who can help you navigate through the vegan newness!!