I feel your pain. This used to happen to me all the time when I started on the guitar. My problem was, even though I was using an electronic tuner / piano / pitch pipe for reference, I couldn't tell that I was way above the correct pitch - exactly what Meaningful says.
What helped me, besides just getting a better ear so I knew if I was around the correct register, was to get a feel for the tension of the string. Since you have others tune it for you, it might help to have it properly tuned, then bend the string some to get a feel for the tension. Then loosen the string so it goes flat, bend it some more so you can feel the difference, then using your tuner of choice, try to bring it up slowly to the correct pitch.
At least for me, after a while I had a good idea of how the string should feel when bending. It took longer for me to notice if I was actually above or below the target note on the tuner - that's ear training and an awesome thing to practice - ear training takes time but well worth it.