I need help with my approach

ok, so this is sort of difficult to explain, but here goes:

I find that when I am improvising, or trying to come up with a bass part, or even just messing around on my bass, I take a "visual" approach rather than a "melodic" approach

ie i don't really think of a melodic line in my head, then translate that to the bass, I just know the fingerboard & know the notes & chord tones in the scale & play whatever "looks" right... though it's not really visual...

I guess I use a "mechanical" approach rather than a "music" approach...it's almost mathematical in a way

It got me thinking, that these 2 approaches sort of divide bass players...some do it one way, others do it the other

NOW, of course I would much rather take a musical approach, so my question is...after 12 years of playing, how do I change this? how do I re-learn>

I *know* I would be a better bass player If I could change this.

My approach seems to work really well for funk.... but a melodic bassline for a rock song? forget it

help!