Need diet (vegetarian) ,exercise and day routine advise to regain lost weight and muscle mass lost due to inflammation caused by extremely bad lifestyle choices.

Hello guys I am a man in early 20s and due to my bad lifestyle (sleep and diet and routine) I lost significant wight and muscle mass due to inflammation in my body. Now my weight is stable but I am very underweight due to which my self esteem has become low.

I want you guys to please recommend me routine, exercise and diet plan (vegetarian) so that I can gain weight and muscle mass and also build my strength.

Also give me height increase tips (if height increase is possible).