I haven't bothered to read the whole thread, so maybe this has been said already, but here goes:
You say you're learning to rely on yourself, but that's not really true. You're learning that you always have relied on yourself. You've gotten yourself this far without help, and you'll keep going just fine.
Sometimes things are difficult, and it's nice to believe that you've put matters into the hands of a more powerful being, but really all you've been doing before is accepting that there are things in life that you can't change and moving on. You can certainly still do that, you'll just be conscious that that's what you're doing. Becoming atheist shouldn't change how well you're able to cope with difficulties, since being theist never actually helped you either - you just didn't worry about it as much.