[CAN-ON] mistake on my resume. Will I be alright?

I made a big mistake on my resume regarding experience. I already got an offer, signed it, and just waiting for background check.

What I wrote was: Research assistant (may 2017 - Aug 2018)

But it should have been Research assistant (may 2016 - Aug 2016) paid, full time Research assistant (sep 2017 - April 2018) unpaid, part time

I did full time summer research, then returned to the same lab later for research course work.

Not only the timeliness was inaccurate, I also didn't include details which could be misleading. It was a while ago when I worked there and I didn't give much care. That was silly of me.

Now after I handed my information to background check company, I immediately emailed recruiter, correcting those with clarification.

I am worried that I will get disqualified due to this mistake. The job I applied was an office admin role.

Any input will be greatly appreciated.