Whatsapp data lost when number changed

I just lost my 6 years whatsapp data.
I recently got a new number and changed the number to new one on standard whatsapp, everything was normal 3 days until I downloaded WhatsApp business so i could use my both numbers, this is what i did:

1) I added my new number on WhatsApp business, everything was fine and all chat data was transferred to WhatsApp business.

2) Then I signed in with my old number on whatsapp standard, which had no data of course as it was transferred to the new number and business account, i got a little confused at this stage and probably messed up here, so:

3) I changed the number on standard whatsapp with my new one which was already connected on the business account, I was hoping that my chat data will get transferred automatically to standard whatsapp however i was wrong, it instead just changed the number on standard whatsapp and no chat data came here except all the WhatsApp groups were transferred here but with no chat history or media.

4) Now when i changed the number on standard whatsapp with my new number that had all the data in business account, vanished... upon opening the business app, i had to sign in again which i did with my old number that had no data.

While doing all this, i had no idea what the consequences would be, in fact I panicked and messed up all this.
Now what i am concerned about is, when i changed the number of standard account at point no.3, where did all the data of the new number (actual data that was previously transferred) go? I do not think it would’ve simply got deleted, i feel it’s a bug and the data is hidden somewhere.

I have attempted to delete the whatsapp and reinstall but WhatsApp does not detect any back up at all.
I also think that i had some back up in icloud, my icloud was 50gb and it was full but after this happened, i have noticed a drop of 4.5gbs from the icloud, i have no idea how this could even happen.

I will highly appreciate if anyone can help me retrieve my data.