You need sleep. I would temporarily up the dosage to .50 and stay on that for a while until I was sleeping well. Then I would start reducing again. You may have been tapering too fast.
A magnesium supplement might help the spasms, but Ally is right, if you're getting heart palps you're tapering off too quickly. Keep in mind the original purpose of benzos was as anti-seizure medication. For insomnia, you can try homepathic remedies such as Calm's Forte, since they don't have any interactions with GABA, which is targeted by the benzo, or melatonin, or both. You might also look into meditation for some peace. Some say fish oil helps with withdrawal, it's worth a try. Good luck.