Being loose aggressive is dangerous since you are playing more mediocre hands which can get you into difficult spots, if you can't get away from those hands you are going to end up losing a lot of money quickly. A loose aggressive player will probably be best off playing at a weak (too) tight table where he can pick up lots of pots (and get away from hands where it is clear that he is beat).

However there is a limit to how loose you can be, if you are too loose you will be a losing player no matter how good your post flop play is.

Being tight is not "natural" since the reason we play poker is to get action and the only way to get action is to be in the hand. Its something you have to force yourself to do. You might want to try multitabling, since you will get more good hands and this will allow you to play more hands.