Climber here, your sessions aren't that hard. No offense. But I've seen and been around climbers of different body sizes for a long time, and unfortunately, you neither gain or lose weight simply by climbing, it typically comes from supplemental. The rest of your activities combined well attribute more to weight loss than anything else.
If your goal's to be a better boulderer, and you want to do that by losing weight, you're gonna have an uphill battle. You're trying to gain strength by but in a calorie deficit.
My $.02 - You're training wrong. Pick a goal and assess what you want. Do you want to boulder V8 next year. Do you want to redpoint 5.12d? Pick your goal and train for that one, once you define your goal you get to choose the right path to get there which includes focusing on one correct discipline at a time.
Hangboard. Ok, so you weigh more than you want to, neat; you've got a built in weight vest. Max the fuck out of your fingers and strength train (yes actually lift stupid ass weights and do stupid ass push-ups and all that bullshit). Don't do this in a calorie deficit. Do this in a surplus on a high protein diet, use your natural inclination to put on weight to put on muscle. Your fingers will get bullet hard.
Now that you have put on muscle, boulder super fucking hard. Make every crux a breeze. Transition from pure boulder to power endurance (doing as many hard as boulders as you can back to back (simplified version)) and then move on to endurance. Once you are in the endurance phase, you'll have a nice healthy mass of fat burning muscle on you, muscle that knows how to apply itself well to hard climbing. Muscle that when resting, will raise your BMR. You then go into a calorie deficit, learn to fight hunger, melt pounds and lose some of that muscle as well, but come out a lighter, stronger climber then when you started the cycle.
I am 5'8" male in my 30s, currently 148 with a shit BMR in . In sport season I try and get down to 134. It only happens with my fitness pal, logging and weighing all my food planning my training sessions 3 months ahead of my normal alpine sport seasonal trip. Right now it's cold. Bouldering is good when it's cold. I like bouldering. So I accept being 148. Enjoy your weight relative to the goals you want to achieve. I have to get down to 1200 cals aday to lose weight, it does suck, and it typically revolves switching from chips and salsa to carrots and hummus and from beer to not beer. It fucking sucks, I feel your pain, but if sending the hard is important, you'll get there.
My rule of thumb is: You never get better at bouldering by sport climbing. But you get better at sport climbing by bouldering. It's winter time, I bulk easier in the winter, use it as an opportunity for a good training plan. Good luck!