Usually i advice to set a bottom line after really big wins and cash out most of it, but naturally , and in this case as you wanted to play much higher for once of course it can rip it all..
still you lost 45€, not 800 or whatever other number came up there. You WON that money, but lost it again. End of the day, you spend 45€, but had the chance to cash out wins.
of course that is way different than depositing 800€ straight up and lose it all imo