Hi, you are telling us all the things you are doing, but it would be nice if you can post a copy of your sketch, using # code tags, a picture of your project and a CAD or picture of hand drawn circuit diagram.
What experience of programming, electronics, building with electronics and ohms law do you have.
Hope to help, but you have all the information and we need it to give you reliable answers.
DO NOT power everything off 12V without regulator circuits because not everything will operate on 12V.
Do you know anything about ground or common negative circuits.
Please a circuit diagram ,if you don't have one, then STOP and draw one up so that you know where you are going.
The sketch, is it one you wrote or someone else that you have combined?
If you wrote it, did you write a section at a time to and get it working or just write it all at once and now need us to debug it for you?
Hope to help.
Tom..... 