I like the suggestions of saturating yourself with positive and inspirational energies. Get back into the 12-step group and actually work on the 12 steps, they're incredibly useful. Be more proactive in noticing when negativity creeps in, find out from which sources, and plug up those leaks, internally and externally.
To be consistently happy, you have to let go of all of the obstacles that get in the way. Rate of happiness correlates directly with level of consciousness, so you might want to look into how to keep raising your consciousness/vibration. As we keep evolving and raising our consciousness, all the lower negative LOC parts of our being will come up to be healed and surrendered. Just keep working on it, and keep your intentions on where you want to go, and sooner or later you'll make it
