You sound like you know even less about training than me!
basically. i can ride fast for a short time. then i blow up.
That just means your riding too fast. Pace yourself, get a heart rate monitor, a cheep £20 one will do and figure out what heart rate is sustainable for a long ride. For me I know that if I'm going to go out for 3h+ then it needs to be under about 160-165bpm the whole time, under 2 hours and I can afford to push harder up some hills, under an hour pushhard on most hills, under 40min (commuting home from work) I can sprint up every hill and ignore my heart rate.
The trick to going faster for longer is therefore going slower. So if you want to do 3 hour+ rides then you need to do 3 hours at a sustainable pace to get your body used to storeing enough energy to last that long. Simple carbs will keep them toped up during the rides, some people like jam sandwiches, bannanas, fruit, dried fruit, sweets, or more complex carbs like flapjacks, others prefer energy drinks and gells.
Mix those sessions up with faster sessions to build the power. Thse can be either just going out for an hour as fast as you can ride for the hour (not very effective). Or going out for an hour, 15min warming up, then spend the next half hour doing some variation on intervals, e.g. pyramids where you go hard for 1 min, rest 1 min, hard for 2min, rest 1 min, hard for 3 min, rest 1 min, hard for 4 min, rest for 1, hard for 3, rest for 1, hard for 2, rest for 1, hard for 1, rest for 1. Then cool down for 15 min.
Mixing up those sessions used to work for me. I've since got fat and everyone else bought power meters and training's got far more complicated. I'm more in favour of keeping it simple and easy to follow. So an example week would be:
M,T,W - do the fast 1 hour session, but make the middle/tuesday session just an easy one to recover form the day before, maybe just ride slightly harder than a long rides pace for the middle half hour.
Thurs - rest
F, S, S - longer rides at a sustainable pace. You should be tired at the end, but not properly broken untill the Sunday.
Monday - rest
T, W, T - fast sessions as above
Friday - rest
(etc, basicly an 8 day pattern)
Repeat for 3 weeks, then take a week off, doing easy rides to recover. The idea is to push the body past it's limit, then it can repair and that limit moves up a notch. Hence 3 days on, 1 off, 3 weeks on, 1 off. It's the weeks off where the recover takes place and fitness increaces.
The other alternative is just get out and ride, I used to do a 25km commute, absolutely nail myself on it twice a a day, and got fast as a result. The same applies to group rides, I now try and ride with various different groups 3 or 4 times a week as it's more enjoyable for me than trying to do structured training alone, and even easier to stick to, the pace is whatever the group is riding at, no need for heart rate monitors, power meters, or even a cycle computer, just try and ride in groups that are going to push your fitness in the direction you want it to go.