I would like to add that while technical practice is important, and I definitely advocate it, you should also be spending a lot of time improvising and playing to blues backing tracks. Speed will happen with time, but if you spend too much time just playing technical exercises, you are missing out on developing the musicality side of your chops. I really doubt Stevie ever spent much time doing technical drills. He would have just "played" his guitar all the time. That is not to say you shouldn't do technical drills, but many make the mistake of practicing technical drills all the time instead of "playing".
I am an avid SRV fan, and learnt most of his songs note for note. This was great for developing my chops, but I realised quickly that I didn't want to sound exactly like someone else. By improvising or trying to come up with your own licks, you will start to sound more like yourself.
I would suggest that, if you were going to practice for 3 hours, do a half hour of drills, and 2 1/2 hours of "playing" to your backing tracks.
Also, get a blues trio together if you haven't already. To be realistic, 10 hours a day practice in the bedroom for 10 years probably won't get you Stevie's technique and power, but 10 years of performing 5 nights a week might. It's a whole different thing. ;)