You should have seen what I went through just prior to my London trip last month. I had planned it for a year, talked about it, researched and then promptly put off all final planning come May. Everything seemed to be another omen of doom: the airline gave me flack about traveling with my powerchair; England chose this year to have the worst summer on record with cold & rain; the exchange rates skyrocketed; my dad started complaining he could walk distances there. When I finally discovered a major compatibility charging my powerchair on UK power systems (a week before I was set to leave), I was ready to cancel the whole thing and stay in my nice warm bed.
What did it matter that I've always wanted to go to England and had been talking about it for a year? It's a foreign country and I might be kidnapped then sold into white slavery!
In the end, I found solutions to my problems and couldn't blow the $2k on airfare so went. I promised myself I'd just see how it went and have an adventure. Sure enough the first three days the weather kept getting worse and accessibility issues did plague me. But my dad enjoyed the walking and we took it all as an adventure. I wrote daily travelogs home and found I had the best time of my life.
Sometimes you just need to treat a vacation as an adventure. Some are more harrowing than others, but all add spice to your life.
Good luck with it!