Boy, I get the frustration of "if only I'd started sooner." But you can only start where you are right now. The good news is that your time to FI is entirely dependent on you! See this article and chart:
http://www.mrmoneymustache.com/2012/01/13/the-shockingly-simple-math-behind-early-retirement. If you save 50% of your net pay, you can retire in about 17 years; if you can increase that to 65%, you can retire in about 10. Etc. And all of that is not counting what you have saved so far.
In fact, you are in *better* shape having discovered Mustachianism than if you were counting on retiring at regular retirement age. When you plan to work for 40 years, the money you invest in your 20s is the most important factor in your success, because the power of compounding is what drives your returns (after 40 years, your 'stache will be more than twice as large as it was after 30 years, even if you don't add another penny, just because of the power of compounding). So if you planned to invest small amounts and let compounding turn them into a giant 'stache over 40 years, then, yes, you'd be behind. OTOH, when your plan is to retire early through Mustachianism, compounding is significantly less important, because you're not planning on waiting 30 or 40 years to use that money! In that case, what will drive your success is your own savings rate, as described in the article above. And that is the same whether you start at 22 or 52. Sure, you've probably missed the "retire by 40" option -- but 45 or 50 is out there waiting for you.
Finally, this is one of my favorite Dear Abby columns of all time -- I keep this in mind whenever I start worrying about starting too late and being too old:
"DEAR ABBY: I am a 36-year-old college dropout whose lifelong ambition was to be a physician. I have a very good job selling pharmaceutical supplies, but my heart is still in the practice of medicine. I do volunteer work at the local hospital on my time off, and people tell me I would have made a wonderful doctor.
If I go back to college and get my degree, then go to medical school, do my internship and finally get into the actual practice of medicine, it will take me seven years! But, Abby, in seven years I will be 43 years old. What do you think? -- UNFULFILLED IN PHILLY
DEAR UNFULFILLED: And how old will you be in seven years if you don't go to medical school?"