The worst thing you can do is to ride the longest, hardest, most challenging ride you've done so far when you are not mentally or physically prepared to handle it.
Don't do this ride when you have had an emotional week at work. Don't do it when you have heard horrible things have happened to two people you work with. Especially don't do it when something horrible has happened to a former classmate of yours on Monday night.
Don't do this ride when you have a career-questioning week at work--when frustration after frustration mounts in your head and your heart and you don't know how much more you can take of it.
Don't do it unless you are prepared for how hard it will be. How stupid and inadequate you will feel as you crawl up hills miles slower than anyone around you. How your average speed at the end is the lowest you've ever seen it. Don't do your first major ride with lots of hills on this day.
All it will leave you with are some tears and a lot of doubt in your mind about whether or not you can really do this in three months.
So just don't.
Take my word for it.