I talk myself out of them because they're out of my comfort zone.
You could sort the things that are outside your comfort zone by how risky they are, then it would be easy to do the least riskiest thing and add it to your comfort zone. Repeating it over and over to add things to your comfort zone. When something is not comfortable just learning about it can let you feel more safe; like how to skydive, how the security mechanism works and at what height to pull the parachute.
I need to earn a living, so taking large amounts of time out seems impossible.
Yes, life consists of sharing between choises. You either go to work and gain money, or you go travelling and see the world. Each choice comes with their own (dis)advantages, it's up to you too choose which one. Of course, such a decision like "I go travel the world" is not easy to make.
Don't do it if you don't have the money for it, unless you can find a way to earn money while traveling. Working in different cities could be an option.
I have too many ideas and can't seem to settle on anything specific.
That's because you want to do something new. The method I describe in the first paragraph allows you to do the least riskiest one, as you are afraid of doing the more risky ideas that might be a good approach into choosing what you want to do. And sometimes you just have to roll the dice and let destiny decide...
I'm not naturally a risk taker.
Although there are risky thing like climbing high mountains, you might be overestimating some risks. Note how it is statistically more safe to take the airplane than driving by car, while a lot of people that never take the airplane are afraid to do so. With bungee jumping, the cord is calculated to not break even under extreme conditions like wind / rain / heavier weight and so on...