Well first off your post is a visual eyesore get rid of the red it hurts my eyes (although I see your new and young* so I guess I cant blame you much)
It seems you are having some trouble sticking with one army I suggest sitting down with your rulebook and the
GW website on your computer and looking at every model which intrests you. Then make a final desicion (if you have 2 armys you just can't chose between flip a coin, if you are disappointed with the outcome take the other choice) then pracitce some self disapline. I know it can be hard (of how many times did I want to be a nid player) when you see that cool new model but stick with it because you'll get one soon to
I hope my incessant rambling helped a bit
* like me