Welcome 5thfret! I assume you're a guitarist. Having a few hobbies is probably helpful. Personally, I'm right in your age range and started daily detecting in 2010. I'll do an hour or 90 min after work, and 2 to 3 hours weekend mornings. I used to go out on the weekends with the "boys" but can't handle 8 hr hunts anymore. I could go longer when I had my T2 (which you know is almost the same as your F75). The Equinox is NOT physically fun to swing.
I'm forced to take long breaks as we get a lot of snow in the northeast CT hills...and don't like to go out below freezing anymore...so I get plenty of breaks throughout the year.
I agree with Del (Dan) in that a compatible partner makes a big difference. With a regular partner you'll experience all the ups and downs of a close relationship. There have even been "break ups."
I agree with you about the permissions being a pain. I don't like procuring them but most times it's another way to form a nice relationship. I've met and befriended many owners who've enriched my life...I sometimes wonder if that's the best part of detecting.
I hope you continue with your current mojo and best of luck!
PS I'm a musician too!