Toddler pulling hair out! Help please!

Does anyone have experience with toddlers pulling out their hair whilst settling for sleep (nap and bedtime). My 2 year old constantly pulls out hair as a soothing mechanism when in her cot for her nap and bedtime. She's starting to get bald patches. She also sucks her thumb and won't take a dummy. We have tried special sleeves to stop her but she gets so upset not being able to get to get thumb. Any recommendations on what to do? It's quite stressful seeing the amount of hair she has pulled out each morning or after her nap.