Recoverying old wallet.dat

So I have an old wallet that I haven't touched since 2018. I wanted to update it. I installed the bitcoin core 0.21 version with the old block folders I had from 2018. I forgot to drag my wallet while it syncing. Now it won't recognize my wallet.dat Something about reindexing. So I retry the process again, dragging the blocks from 2018 and resyncing but this time with the old wallet.dat in it. Now it just crashes the moment it reads the blocks at March or May 20 2017. I tried again with fresh blocks downloading. It kept crashing at the same date. So I was getting worried that I lost all my coins. So I checked my old addresses. According to the blockchain explorer the 3 receiving address that I used for transaction return nothing in the wallet. That's weird. I never touch the coins since.

Worrying that i lost over 10-15k, I did the pywallet method on my encrypted wallet. Now I have like tons of addresses that I never seen before in the json txt dump. Is the private keys the "sec" line? Do I have to manually add every sec/secret key to a new wallet. Is there an easier way to transfer private keys? I noticed at the bottom of the dump text file it said ver 150100. Does that mean this wallet.dat is from bitcoin core 0.15? Can I try again with the 0.15 version? Kinda wasted a whole week and it's stressing me out.

Also every method I attempt to, I used a copy of my backup of the old wallet.dat. Just in case, the wallet.dat get corrupted. I know I have left over coins. It can't be empty.

Also I would like to note that I am using Windows 7 if that makes a difference.

Edit: now checking with my old electrum wallet. I have made some movement with the bitcoin core but the drive that had the bitcoin core wallet at 2020 was killed in a miswiring. So I am using a back up wallet from 2018. Is it possible recover coins that was in the 2020 drive using the 2018 back up wallet?