AFAIK Bitcoin Core give new address every time you choose generate/show receiving address
Bitcoin Core never remove address or wallet.dat, unless instructed by users

But, you should check all of your wallet.dat address first. It's located on menu bar ("File" > "Receiving Address...")


Recovery phrase? AFAIK Bitcoin Core only support that in form of master private key. Just to be sure, is it human readable (contains multiple words) or only contains 1 long string?

p.s do not share/post your recovery phrase