Answer:
"Going to the theater alone is a very EMBARRASSING experience for me."
The word modified by the participle is experience.
Step-by-step explanation:
Adjectives can come in many forms and often they come from past participles of verbs. Their main function, as any adjective, is to modify a noun, a noun in which they agree in number and gender. Participles that can be used as adjectives often end in -ed or -ing.