My advice is to eat every 2-2,5 hour.
Make sure every meal will have 25g of proteins and min 60g of carbs and about 10g lipids.
Dont waste money on gainers. (you can have 60g of gainer + 30g of WPC pior after workout) but during the day blend 60g of oats with 20g of chocolate spread.
Instead of having a shake before the bed time have some quark cheese with milk and olive oil.