Im already too thin . will creon help gain some weight?

It's hard to know as I'm not sure what your problem is.

Creon is a pancreatic enzyme supplement used in a condition called pancreatic exocrine insufficiency where the body does not make enough enzymes to digest food. This condition appears in a number of different patients including those with cystic fibrosis, chronic pancreatitis, or patients who have had upper gastrointestinal surgery. People with a deficiency of pancreatic enzymes often suffer with symptoms of diarrhoea, steatorrhoea (foul fatty stools which float in the toilet), bloating and weight loss. These symptoms appear because the body is unable to digest food normally. When this happens your body's ability to absorb important nutrients from food is impaired and leads to malnutrition.

Creon can help to restore the normal digestive action in your body to relieve abdominal symptoms and improve nutritional status.

https://www.drugs.com/creon.html