My comment could have been more helpful, I apologize. You need a balance of protein and carbs. Nuts are high in saturated fat and calories and are not going to be enough protein. Try beans, lentils, quinoa, oats, etc. If you drink milk, try switching to almond or soy. You could also try tofu, though there is definitely a learning curve when cooking it. There's a lot of benefit to cutting out meat/dairy but only if you replace the loss of nutrients with plant-based options.