HireRight BC is killing me! Can anyone advise on this?

Just received a great job offer, but I'm going through the HireRight BC, which is raising my anxiety through the roof. I only have contacts from former workers at the majority of the companies they are checking, and most of them don't have a HR department, so I can't provide contacts of this type. They also asked me documentation to prove my start and end dates, but I only have the paysubs and contracts, I have no official documentation saying that my contract ended on the mentioned date (these were 6 months contracts were they just sent me an email or notified in person they did not want to renew). Do you think the contract and last pay subs will be enough to confirm my employment? I'm afraid of losing this offer just because they might not be able to contact these companies.