
That bending usually means two things :) The needle material is flexy or the stitches are tight enough to put a lot of torque on a thin shaft. Thin sizes and long straight needles bend most and especially plastic in warm hands.
Try easing your tension before you swap tools. After you make a stitch, resist the urge to yank the working yarn. Let the stitch sit on the full width of the needle, then give only a tiny snug. Cast on with a stretchier method and bind off without pulling hard. Hold closer to the tips and slide stitches forward often so they do not bunch in the middle where leverage is highest. Support the far end of the needle against your body or the edge of a table to keep it from flexing. If you have a larger size on hand, swatch a few rows with it for scarves the gauge can be looser and the fabric is still fine.
Keep needles out of sun and heaters since warmth softens plastic and can warp wood. Store them flat rather than leaning in a jar. If a plastic needle has a slight curve, soaking it in warm water for a minute and letting it cool under a heavy book can help. For metal, roll it gently under a hardback on a table to true it. Do not try to bend wood back. If you can borrow a circular needle, even for flat scarves, the short rigid tips with a flexible cord reduce leverage and are friendly in a small room. Between looser tension and reducing leverage, you should see the bending stop.