As mentioned there are zillions of patterns you can use. Asking for help on the Internet will get answers using a multitude of patterns -- which are all good and have value. My suggestion is to stay with the book or instructor you have been using, i.e. stick to one method and after you get that down then think about checking out some other patterns. Here is the pattern I use, if you like it help yourself.
I have my own set of patterns that I use and are happy with. Everything I do is based upon the following Major Scale Box. And yes I can take that one pattern up the neck into three octaves.
Major Scale Box.
G|---2---|-------|---3---|---4---| 1st string
D|---6---|-------|---7---|---8---|
A|---3---|---4---|-------|---5---|
E|-------|---R---|-------|---2---|4th string
Pick one you like and stick with that one.
As you have already been working with scales - and that is always the first thing we should do, but, as the bass is a rhythm instrument primarily responsible for playing harmony, not melody, I'd suggest you spend your time with constructing bass lines from the chords being used in the song, i.e. move from scales to chord tones and spend your time with harmony and leave the melody to the treble clef guys -- for now. Nothing keeping you from using scale notes in your bass line, lets just turn our attention to harmony right now.
Scales and modes have their place, but, IMHO after you understand how to make a bass line from the chord's tones. Using the root, three, five and seven scale degrees of the chord's home scale. Most start with roots on the first beat and the 3rd beat and when this gets old bring in a five and or eight. If you need more than that there is always the three and seven. Four note phrases based around the chord tones of the active chord. Ed Friedland's Building walking bass lines would be time well spent. So would
www.studybass.com. At studybass this segment has a wealth of knowledge waiting for you.
http://www.studybass.com/lessons/common-bass-patterns/about-common-bass-patterns/ Yes, click the "next lesson" at the end of this screen.
Find a book or a teacher and settle on one method.
Have fun.