i'll propose something radical....
try exercising early in the morning - namely running
start out slow and short, run walk for five hundred meters twice a week for a couple of weeks, step it up to three times a week, then make it a 1km run once a week and two 500m runs, then two 1km runs and one 500, follow that pattern of progressive overload until you're running 2 or even 4km three times per week
get a gym membership or home gym if you can afford it and have someone qualified write you up a program (don't lift weights more than twice a week regardless)
give up caffeine, don't drink more than a few drinks at a time once every fortnight, regulate your diet to avoid sugary foods, start taking a multi-vitamin and fish oil caps, and vitamin b, drink tap or bottled water throughout the day at least as often as you drink anything else
try doing something you wouldn't usually do on the weekend, take up kite surfing maybe
whatever it is that's keeping you awake when you think about it, ask yourself if it is actually a rational concern, or if you're just worrying about something silly because you've got a lot on the table at work
actually try really hard to focus on specific things that are troubling you and logically consider them one by one. just ignore all the other things racing through your head and disregard it as background noise. if you have to, talk to yourself - this sounds stupid but it's actually a very good way to focus the cognitive mind, which is why the crazy homeless guy on the train does it
i think if you seriously commit to it you will see results, it's not the silver bullet answer and it's a long term strategy but it's your life, so i reckon it's worth the effort