Can't get the embedded phpbb3 forum to work

[Dysphoria]

Hey, I'm back again. Ever since I've got my ssl certificate and forced https on all webpages, my forum has been acting strange. Everytime I want to log into ACP I get redirected to my front page on wordpress or another page saying they couldn't find the web adresse. I've tried to uninstall everything, even de forum. I installed everything back again, but there is still this issue. I think it has something to do when I tried editing everything to https, but I don't know what to do. I can't edit anything on my forum, because I can't get into ACP anymore. I edited the codes to https, so it's not like I forgot that.

[axew3]

have you try to disable javascript on browser, and access the phpBB (using https://...) with direct url, then login, then login ACP, and change settings? Also may clean cookies!

[Dysphoria]

I've installed it again, I think I know what was wrong. I probably forgot something, again. I'm going to test it and I'll let you know.

[Dysphoria]

I tried to install everything back as I did before, but now I get this error when I try to go to my board:
HTTP ERROR 500

So I can't do anything anymore inside acp.

And when I try to upload my precious files from my backup folder, it's still broken.

[axew3]

You say you reinstalled the board, and now you get this, but
Error 500 mean many things: what about your (root phpBB) .htaccess file?
Is the default one?
Did you uploaded in the while, and overwrite some phpBB file with wrong chmod premission?
Have you try to execute the chmod with right permissions to all files and directories, if you uploaded again some files?