Someone asked about your gearing. I'm a little heavier than you (and probably a lot older) and I need low gears for climbing. I use a 34x29 for about everything.
I also sweat a lot and I have to force myself to drink enough and if it's a hot climbing ride I can't keep up. I get nausea when I get dehydrated. I have drank over 200 ounces of liquid on 7-8 hour rides.
When I do climbing rides I weigh myself before and after which gives me an idea of my hydration loss. I have come home 11 pounds lighter, 5 or 6 pounds is about normal. You can also check the color of your urine. If it gets super dark and doesn't happen very often, you are dehydrated. A few weeks ago I didn't pee after the ride until late that night.
A lot of this stuff is just learning your body and how it responds to what you are doing to it.
Last edited by big john; 09-22-19 at 05:23 PM.