Giro, I sympathize because I too am running projections to see when my retirement date can be. I'm trying to keep those recalculations to once a quarter, so it's easier to ignore the volatility. I saved 80k for retirement last year, but market performance and sale of our clown house at a loss meant my net worth was basically unchanged over the course of the year. Another year older and no closer to the goal, despite running very fast.
I did the same thing you did - considered changing approach. I had the same reaction to my business goals 18 months ago when my business hadn't yet taken off. I was doing all the right things but the results were disappointing. So I carefully reviewed my approach, made sure it was right, and just trusted that things would turn around if I kept working at it. And, they did. I'm hoping our investments are kind of the same deal - we're making the right choices, we can't expect the returns to always be positive growth.
Your date's a lot closer than mine, so you're subject to more of the rollercoaster ride. You know the number you need to hit, if you need another year to get there, just push out your target retirement date and re-evaluate it in three months. Try to focus on achieving the savings goal, not meeting the time goal.