I am relatively new to BTC but i’m all in on the principles behind it. I know nothing about coding or cryptography, but I love the concept of decentralization and I am a huge Austrian Econ nerd.
I had about 0.045 BTC in Coinbase Wallet, and transferred about 1/3 of it to my Bitcoin Core node on my macbook for the sake of having it out of a centralized exchange. I’ve been running the Bitcoin Core software for about a year and a half now, but never used it as a wallet until a week ago.
On 9/22/24, at 1500EST, the Core app stopped synchronizing with the network. I did some research as to why but didn’t make any changes. This morning, 9/24/24, I decided the best thing to do would be to increase the RAM allotment for the Bitcoin Core app in the preferences. Several people on various forums said this helped them when the Core app stalled in synching with the blockchain.
A dialogue box popped up and said I needed to restart the app for the change to initiate. I did so, and then everything went to hell.
As soon as I reopened the Bitcoin Core app, the following dialogue box popped up 
[You need to rebuild the database using – reindex to go back to unpruned mode. This will redownload the entire blockchain.
Do you want to rebuild the block database now?]
When I selected {OK}, this dialogue popped up next. 
[Error: Error opening block database].
When I select {OK} on the second dialogue box, the app crashes.
As I said, I am relatively new to Bitcoin, and I have gone down the principles rabbit hole for probably over a thousand hours, read Bitcoin Standard, Layered Money, Dom Frisby’s Books, listened to every episode of Breedlove’s What Is Money show, etc. But I don’t really have expertise on the use of the app, or of command prompts or coding whatsoever. I also, like a complete fkn idiot, did not write down my private key, as I didn’t even know how to extract it from the Core app, and I hadn’t dedicated that much time to figuring it out because I really didn’t think I would need it yet. Lesson learned.
Any wisdom regarding how to get the app to work again, how to update it, how to force it to start reindexing immediately on opening, how to find my private key from the db files, etc would be EXTREMELY welcome. Like I said, I only have about 0.016 BTC in this wallet, which isn’t a crazy amount, but it’s not nothing (~$1000 as of 9/24/24) so yeah, please and thank you to anyone and everyone here who might be able to throw me a rope.
