I'm afraid to get my 2 year old checked out!

My little girl is VERY clingy to my husband and I. She is terrified of random things, like when it rains, or if someone she doesn't know comes to close to her (even if she's right next to me). She goes to the nursery during church with her siblings, it took months to get her to the point I could leave her in there, and if there's a child that's new she freaks out! She's down to one night terror a week now, but it used to be three nights a week. If she gets excited, she shakes really bad. If she gets scared for whatever reason, she tenses up and her face will go blank and she won't blink (sometimes for two or three minutes! ) she's a smart and sweet little girl. Nothing bad has ever happened to her other than an occasional time out.