ITT a lot of good input on why helicopter parenting is bad, why her intimate relationship with her BF sounds pretty normal and also (no offense) not your business. Her actions toward you aren't pristine either, but the part about your heart breaking are why I felt compelled to respond.

I can say as a woman in my late twenties, my early twenties were horrendously ungraceful. I feel better now that I'm well into the plans I made, career path has been walked for awhile now, decisions in love have panned out, etc. But 6-8 years ago, my parents showed extreme patience while I figured this out. I too am the baby of the family, and like you, my parents have a policy that my sister and I would sleep in separate bedrooms from our boyfriends until we have rings on our fingers. This was even true for my sister while she was cohabiting with her future husband. It's been easy for me to respect this rule because A). thin walls and paranoia kill the mood for me and B). I haven't lived with them for more than a week since I was 18, so there was ample time and space for that anyway. Her shutting down to your policing of her love life is how I would have reacted too. Falling in love is awesome, they'll have sex in her room whether he shuffles to a new bedroom or not. And waking up next to someone you're intimate with is what separates lovers and friends with benefits, IMHO.

But you seem like a really sweet and good father, so take what she says about not wanting you in her life with a grain of salt. I've said things that were also so hurtful in the heat of passion, in the emotional throws of fighting to show my parents I was growing into the kind of adult I wanted to be. They taught me to think for myself, it just shook them that I ended up thinking differently than them. So the culture / age disconnect has been hard, but as time went on it got less stressful. I was also the baby of the family, spoiled, and wrapped up in all this "who am I" nonsense while I got my degree. It sounds like she knows she's close to the day when you won't get to know if she's home at night, like it or not. My mom says "wait till you have a child, it's terrifying, and I'll never stop worrying." While I can see her side and know I won't fully empathize till motherhood, I still shut down when irrational amounts of tracking are employed. I remind her that she taught me how to be safe and accounted for, my friends and I look out for each other, and I avoid dangerous situations when I can. So even though your daughter isn't the most mature in handling things, she's pushing forward towards the life and freedoms she wants.

My point is that she probably definitely still loves you, and this will probably pass. If monetizing her time in your house (and your time, cleaning up after someone isn't fun [and will only be worse for future roommates that aren't her relatives]) is the healthiest thing for your relationship, by all means do it. In a couple years perhaps all your financial ties will be severed and all your conversations will be about sportsball and Uncle Jackie and burritos. And years and years later: how tough parenting is. For now, yeah things sound stressful and clashy, but you're not loosing her in the larger sense. Have faith, it sounds like it'll be alright, just not simple.