Kira

While I was out riding my bicycle today, I noticed that there's a problem with the front derailleur. I shifted down to the lowest gear in front, but now I'm unable to shift back up.

When I try shifting up, the derailleur doesn't seem to push the chain far enough for it to move to the next gear, instead it just barely touches it. I've adjusted the limit screws a bit and tightened the cable, and now I'm able to shift back up to the middle gear (I have 3 gears in front) after a few tries. However, there's still a problem with the levers I use to shift.

I have two levers for the front derailleur, one to shift up and one to shift down (obviously). When I've shifted up to the middle gear, the lever that I use to shift up doesn't work anymore. There's no resistance, as if the cable is loose. If I push the other lever even slightly, the derailleur snaps back to the lower gear (instead of gently pushing the chain as it normally does).

The shifters and derailleur are made by Shimano, but I don't know what model they are.

Unfortunately, I can't afford to bring my bicycle to a mechanic, so I hope someone here will be able to help me out.