What? Some random "girl" on Tinder introduced you into some investment scheme and you just believed everything without first doing some digging for information?
Well, It looks like the €7,000 was tuition fee for you to learn that there are so many cryptocurrency scams around and you should always carry out due diligence before sending out your money.
If you wanted to "invest" why didn't you just buy Bitcoin? Its price has more than doubled in the past few months, You should be having more than €20,000 worth of BTC by now. Clean and smart money, safe in your Bitcoin address.
Lol'd at the tuition fee joke. Well played sir