Ah...a trap most of us stumbled into.
If they say they don't want a relationship or any variant there of (eg: "I'm not sure what I want right now") it always means - "I don't want a relationship, with you, ever'. Always.
And if they then go on to be all intense ect... they are a big time head fucker.
Rule of thumb - 'intense isn't good news'. Nor are 'whirlwinds'. They usually mean you're dating a love bomber. And most people who do that are abusers. Some exceptions during youth perhaps due to inexperience...but I probably wouldn't make that for him.
Always look to see if actions match words. If they don't, then run.
But yeah, 'I don't want a relationship' is ways a big neon flashing red light. Walk away. Unless you just want a bit of fun. But in my experience they don't want YOU to have fun.
If they're trying to make you catch feelings after they've already told you they don't want a relationship- they are mindfuckers. Headwreckers. Very bad news.
We often make the mistake of thinking 'they obviously want me to like them so they must like me'. No. No it doesn't work that way. They just want to be put on a pedestal.
Amd they'll use 'but I TOLD you I never wanted a relationship' the second they see someone else they like/decide you like them a lot and they've got all the admiration they needed from you (or sex) for their ego stroke. They may even move into abuse then in order to get their kicks (eg: a cycle of love bombing- then devaluing you - then discarding you).
They'll maybe even act all smitten but the second you ask for clarification they make out YOU were thr full on one and are smothering them. It's a trick and a trap.
I would run fast love.
Don't worry, it's a mistake many make. Often more than once. You've done nothing wrong or stupid. But,now you know.