Fruits mostly contains soluble fibers, only their peel contains a bit of the insoluble one. For your next try consider instant mashed lentils/slip peas (flakes) or lots of mushrooms if you're rich enough. Adding a fair portion of hemp or nutritional yeast also increase the protein ratio. And tempeh is really a game changer. I wish the best for you.
I can eat a block of cheese a day and feel great. same with extremely lean chicken. When I try plants only without the problem foods, my energy and recover drops. I get depressed and I have huge protein cravings. If I try to squash that hunger with fats or carbs, I get fat. Just never been able to find a sustainable solution for my body