I am 6'3" I started back riding at about 260lbs on a full suspension aluminum MTB at around 250lbs I bought a carbon fiber Cutthroat at about 240lbs I started riding homebuilt steel bikes all mostly on 28 spoke wheels. I have not had a problem with breakage. You should be fine no matter the material.
Look into a carbon gravel bike with hydro disks and through axles, it is expensive to switch from mechanical disks to hydro disks.
This is a good time to buy a new bike as they close out the 2019s
One example
Niner RLT 9 RDO carbon fiber about 1k below msrp