Hey if anyone could give me some advice I would greatly appreciate it.

Back story: I have been playing guitar for about 4 or 5 years now and I took lessons for 2 1/2 years or so. My guitar teacher was very good, but he seemed to lack the drive to help me learn. I never really properly learned how to create my own songs. I can play guitar well (not amazing, not bad), but I want to seriously start making my own music. I can't read music, I'm trying to train myself to play mostly by feel and I've done pretty well so far. I can create simple songs with just basic feel of the guitar, but I want to know the proper way as well to help further my playing.

So, if this helps you to understand where I'm at skill wise, please lend me your advice...where should I go from here to perfect the art of song writing. (aka, should I focus heavily on understanding music theory? should I focus heavily on learning to read music...etc?)

Basically, I don't know where to start and I'm afraid to start focusing on the wrong thing in fear that since I'm already a somewhat "skilled" player, I will end up having to back track or something.

Thanks, I greatly appreciate the help if anyone can give me some pointers.
Play random shit and never pay attention to theory rules. If it sounds good to you, use it. The more you mess around with the riffs you come up with, the more you learn how you write personally.
I hate people. Especially black people.
Learn all the notes on the bottom two strings. On top of that, I would at least understand how modes work so you can improvise and write progressions quickly(see: http://www.zentao.com/guitar/modes/#Introduction ). You will be able to transpose anything. I recently started writing my own stuff after improvising, or "jamming" with my favorite music online. Some of the greats learned guitar by playing with the radio.