My federal return was accepted. I ammended it, made a change and it was rejected. Will my original return still be processed. I've been waiting since March 1st for.

If the amended return was rejected then you have nothing to cancel as it was never filed  AND  you had to wait for the original return to be fully processed and the original refund is in hand  so it is a good thing the amendment was rejected.  WAIT  for the original return before doing anything else. 

If you filed before the tax law  change… the IRS will recalculate your return for the new unemployment exemption for you. There is no need for taxpayers to file an amended return unless the calculations make the taxpayer newly eligible for additional federal credits and deductions not already included on the original tax return.

They are starting to go out. See this new IRS article May 14, 2021
https://www.irs.gov/newsroom/irs-begins-correcting-tax-returns-for-unemployment-compensation-income-...

And this one from 6/4/21

https://www.irs.gov/newsroom/irs-sending-more-than-2-point-8-million-refunds-to-those-who-already-paid-taxes-on-2020-unemployment-compensation 

You may need to amend your state return,
https://ttlc.intuit.com/community/state-taxes/help/do-i-need-to-amend-my-state-return/00/2134732