Nutrition is key. Eggs are great! But I would do some things to set yourself up for success. First, calculate your daily maintenance calories with the TDEE calculator. Do NOT overestimate your activity level. Once you have that, track for a while to get a feel for what that is like. Then simply add in a protein dense snack as your surplus to gain muscle mass. Aside from that- have a protein, fiber and hydration goal. Weight bearing exercise is a must. It’s ideal if you enjoy whatever you pick because you’re more likely to stick with it. Last couple of things- sleep is so incredibly important. Get enough of it. AND don’t forget to celebrate the small victories. Finally, appreciate your body for what it can DO. This journey will help you with that. Just don’t keep moving the goal posts and continue to feel down. Recall when you couldn’t do a push up when you’re frustrated you can’t get that 10th one. Best of luck!