Wait. What?
You get way more than 70 JP a day. Every heroic boss drops Jp, you can get a ton of JP's a day depending on how many heroics you do.
Also, I don't know in what country you play, or on what servers (US, EU so on), but if your heroics don't get past the first few trash pulls it could be you? I mean, maybe you're a bad tank, or a bad healer? But find a guild.... most heroics aren't hard, especially trash, but if you apparently have as much bad luck as you say, find a guild to be more on top of the ball.
My money is on you're a bad tank or healer and need to more than anything read up and learn what you're doing. If not, just hang back and do normals, and keep trying out Heroics, I've had only one group fail on trash, and that's because the tank was terrible.