Baby getting Startled

My little boy is 8 weeks old and whenever he is in his bassinet he wakes up from a sleep getting startled to the point he goes bright red in the face, and this morning he woke up all fine and I took his blanket off of him and he started screaming and became startled throwing his hands up in the air.

I don’t know why this is happening 😢

UPDATE

Thank you everyone who has commented ❤️, I swaddled him last night and I didn’t have any problems and he also slept for 7 hours last night 👌🏻