Personal Growth While TTC

OK, ladies, I need your bright thoughts and advice. We've been TTC for almost 3 years after having a miscarriage. It's been a very emotional and at times frustrating rollercoaster. I've put my whole life on hold while TTC this whole time and it's starting to drive me crazy - time goes by and we still don't have a baby, plus, I'm not going anywhere personally - I have a good job, but I feel I can do something more challenging and better paying, in fact, I'd love to start my own business; I'm educated, but I'd like to get more education; I run and want to run a marathon one day, but so far my longest race has been a 5K... I'm trying to be "careful" with everything in my life hoping every month that that month will be the month and we'll have a baby. How do I "snap out" of this state of mind and start acting to get ahead in life despite the possibility of getting pregnant? Please, no fertility advice - we know why we haven't been successful so far. Thank you!