Hi folks,
My computer crashed while syncing wallet today.
I could not start it again, so, I erased all blockchain and started downloading it again.
Now my wallet is stucked "downloading headers" with "7 days behind".
Any tips?
Thanks in advance...

Looks like a wallet corruption issue.
OPTION AUse a backed up wallet you know was working prior the crash.
OPTION B1 - Bakup wallet by making a copy of the wallet.dat file somewhere of your choice -- IMPORTANT -- VERY.
2 - Dump all private keys through command line (try dumpwallet first if that doesn't work then try dumpprivkey "yourxcnaddress") - If none work, well seems your fucked as the wallet might irreversibly be corrupted. Pray or contact the devs of the coins.
3 - Once the dump is done delete all the content of the blockchain folder -- ALL -- including the wallet.dat (you have made a backup anyways).
4 - Once the above is done, relaunch the wallet (this will recreate a fresh wallet.dat file), let it synch -- FULLY --
5 - Finally, import the private keys of each address you received coins from and addresses you've created (use the importprivkey command) - All coins should now appear.
6 - Now backup the wallet again so you can use that one in case of future corruption.
That's how it worked for me and a few I've helped.