I for the longest time just let my hair grow long until my parents would force me to cut it down, and then I'd only cut it medium length. Then on one date when my parents were like "you have to cut your hair short for a job interview - they're gonna think you're weird" I was like, ok fine.
I looked myself in the mirror and what I did was basically look for a character I thought my hair could pull off - a style that I could have the salonist cut down to bit by bit. I ended up landing on Haruka Tenoh (a personal hero character from sailor moon whom I borderline worship) and her short cut hair. Sure, on a boy it just generally looks like a boy cut but the way I looked at it I was getting a girl cut to replicate one of my favorite girls from fiction. Even if nobody else really notices, it makes me feel happy looking at it - its my own personal 24/7 crossdress and nobody is anymore the wiser. That may sound silly, but I think the mindset is important on your look and not just how you think people with perceive you.
Picture in question:

I assume you have longer hair at this moment? My recommendation is grab hair styles you like from guys you think you could, in theory, pull off. Grab a few styles of varying lengths, then go to whoever does your hair and work down - do a long male cut, then a medium male cut, then a short male cut - and stop when you get to the edge of your comfort, and what you think you can pull off. The amazing thing about head hair is it grows back incredibly fast, and it being long atm is working far more in your favor than you may think.
And I empathize, I really do, with what you're aiming for - but at the same time, I'd simply warn you not to fall in trap of walking around super stressed about your hair and how it makes you look. It isn't the same in a practical sense, but if you just worry hard about how boyish you look now then it may be harder to adjust further into the look because then you're just jumping from one uncomfortable stressful look into another - the most important thing is how you feel in your own skin, so find a hairstyle that you find boyish enough to be comfortable in and then own it; chances are if you own it and sell it, people will buy it.