Honestly, I didn't read every word of every post on here yet...but I think I have the main idea. I have a few ideas to share with you.
1) Slow down a bit. Sounds like you're trying to CRAM for a test! Sounds like you're trying to learn some of everything at the same time. You are breaking an hour up into 15 minute chunks on separate aspects of music. I think that's going to make it VERY difficult to learn ANY of the aspects very well. How about you separate it into DAYS? It may be a better idea if you schedule yourself, for example: where the first practice day of the week is your theory day. The next day is scales and arpeggios. The next day is timing and right-hand technique...and so on. (however it works out best for you) You need to give your mind and your muscles time to "remember" all this stuff.
2) If you are teaching yourself music (and I've done this), you need to act like a school teacher to yourself. That means, you need to make LESSON PLANS for yourself. How many pages in your music book will you cover in a week? Plan that out ahead of time. Don't just jump in the book and see how far you get...plan it out! Write down that you will do, for example: Chapters 1 & 2 this week...or just ONE chapter..or whatever. If you are struggling in an area, do what a school teacher would do. Slow down, review the material, stay on it until you get it, test yourself fairly (e.g. with a metronome).
3) Be able to teach someone else. The true sign of being a Master of something is being able to explain it to someone else. Can you explain what you learned to your friend? or even to yourself in the mirror (if you don't have a buddy who's into music)? I'm not saying try to turn around and be a music teacher. I'm saying that ONE of the self-tests that you can give yourself is to be able to explain it. Your school teachers use this too, right? They said, "Kingprawn, stand up in front of the class and give a 3 minute speech on (whatever)." Same deal.
4) Make SURE that you are using good quality, trustworthy materials. Everyone and his dog has a music book for sale. "Learn how to play guitar like Jimi Hendrix in 30-Days!" and all that trash. Select books and materials A) that you understand; and B) that teach you something. Read the music book in the book store and ask yourself , "Is this going to answer my questions and teach me anything?" What questions do you have? Did that guitar/bass/music book answer any of them in an intelligent way? Think about that BEFORE you buy the books.
5) Relax and pay attention to your WHOLE BODY! The only way to play fast and accurately is to have minimum tension. If you tense up your hands, you can't move your fingers very fast. So the whole body needs to be relaxed. To do this, you need to constantly pay attention to your whole body (how you sit or stand, your guitar strap, your shoulders, your arm, hands, etc.) while you practice. Music is a gift from God for us to have FUN and to give back to Him in praise. It's nothing to get stressful for fearful over. Just relax and have fun. Is God going to make faces at you if you play a wrong note? NO, He will not...so relax...nothing else matters.
6) I almost forgot to share this! The bass player's job is to control and "feel" (the mood) of a song. To do this, FIRST, you have to be playing in the correct time. You MUST be able to lock into the timing and rhythm of the drummer. So, you really NEED to practice with a metronome. Some things you will need to do at no-tempo practice, but when you are learning a song you need to practice with a metronome (or drum machine or drummer) to make sure that you are also learning the timing of the song. Once you have built some skills in that area...
7) Study some of the arpeggios and patterns of some of the great bass players. Different styles (genres) of music have different patterns in them. Learn to recognize these patterns and these differences. For example, Country music or Bluegrass music usually uses different patterns or arpeggios than say, old Motown tunes. James Jamerson was an amazing player and basically created and defined the Motown sound of the 60's...but his style is not the same as Disco or Jazz or whatever. Learn what makes them different. So study the styles of some of those great bass players of popular music from yesterday and today. You can whip out some super groovy lines by learning some of that stuff and just tossing a little bit in your bass lines here and there!
Probably THE BEST music theory book that I've ever seen (that won't bore you or make your head hurt) is
Edly's Music Theory for Practical People.
Also, you can learn proper techniques for reducing stress and muscle tension in your practice sessions
here.