The main thing I had to get comfortable with in order to ride alone is basic bike maintenance. Just knowing that I don't need someone else's help made a big difference getting me started. If you're already at that point, my best advice is just to make yourself do it on a regular schedule to start, and you'll get used to it. I started regularly riding alone about a year ago and now that I'm in the groove I don't think twice about heading out by myself. I'm in a similar situation where either our local group rides start way later than I'm willing to start (I'm ready to go at 4:30 and they don't start until 6:30? what do I do with myself for two hours in between?) or the starting point is a pain to get to (I'll drive to the start if I must, but I prefer not to).

good luck!