You startled me, because I hadn't heard you come home.
He glanced over my shoulder with a startled expression.
I got startled when I went to my room and my brother jumped up in front of the door suddenly.
Startled is the verb in your sentence.
The startled young colt ran for shelter under its mother.
The startled deer zigzagged out of the underbrush and was gone in a flash.
The spelling is startled, as in The trick STARTLED him.
Yes, "startled" is the past participle of startle.
Surprised almost means the same as startled.
I was startled by a sudden noise.
No. Startle is a verb. The adverb form is "startlingly."
I was startled awake by the fire's crackling sounds. The lightning came crackling past my head and struck the tree.
The grotesque mask startled her.Grotesque gargoyles perched on the roof of the building. The zombie was a grotesque parody of life.