If you’re saying you think you’re too heavy to climb: while that may be true now, you could consider using that as an activity target. That is, you want to be able to do the thing, so you can figure out a plan (which might involve a doctor - I don’t know your situation) that gets you on a trajectory such that you will be able to get into climbing in a year or two. It won’t happen overnight, and it will likely not be easy, but you can get there!

Fwiw: I recently lost about 10kg and am doing well with keeping it off, mostly with just conscious lifestyle changes (portion control, forcing myself into more active habits, being more judicious - though not puritanical - about my food choices), and the difference in my average energy level is frankly remarkable.