What red said, and also when I keep hitting something with my right foot, it's usually the front derailleur cable. You can bend the end of it back out of your way. If you want to cut it closer to the clamp, be sure (1) you leave enough spare cable to grab it with pliers without flattening it too close to the clamp, and (2) you have something ready to cap the end right away, which can be a cap and crimping tool, appropriate sized shrink tubing (sorry I don't know the gauge, but it's the smallest size that comes in wiring kits, I think for 20 ga wire??), or in a pinch, duct tape.

Also, when the riding is hard is when you need to really focus on form and fit. No matter how hard it is to push the pedals, it shouldn't make you get all crooked on the bike as you describe. Something else is going on with your body...