boyfriend of 6 years blew €70k on an online girl

I am in absolute shock and physically sick. My boyfriend and I are both in our mid-20s. Neither of us makes much money, and we’ve always had to budget carefully just to get by. Even though we struggled financially, we loved each other and I really believed we were a team built on trust.
Six months ago, he received €70,000 as his share of his late grandparents house after it was sold and split among his siblings. We couldn't believe it. After years of barely scraping by, it felt like a miracle. We were over the moon and decided to put all of it aside so we could finally afford a deposit on a small home of our own.
For the past half year, we were looking at properties, daydreaming, and planning our future together. Everything seemed so hopeful until yesterday.
He is the type of person who usually takes his phone everywhere—into the shower, to the bathroom, everywhere. But yesterday, for the very first time, he rushed into the shower and left his phone on the bed.
Suddenly, a notification popped up on his screen. It was a message from that blue app (O.F.) from some woman..
My heart completely dropped - why would he be using it???? The screen locked, but on my third guess, I managed to crack his passcode. When I went through their chat, my stomach turned. It wasn't just custom videos.. he was sending her photos of himself, and she was rating them and sending back explicit content in exchange for huge sums of money. I saw thousands of dollars being sent in single transfers…
When he came out of the bathroom, we got into a massive fight. He broke down crying, begging me not to leave him and repeating that it was a huge mistake. I pushed him to tell me how much money he actually sent her. He tried to evade it, but I forced him to open his banking app right in front of me.
There was only around €1,200 left in the account. Almost the entire €70,000 was completely gone in only a half year...
He promised me he would cut all contact and end it immediately, but I feel utterly destroyed. He threw away our entire future, our home, and six years of a relationship for a complete stranger on the internet. I'm staying at a hotel right now and I just can't come to terms with this.