I am so sorry to hear about your awful experience! In the future, you can ask her to first use a the smallest speculum she has! And if she can get a good view, that’ll be the speculum you’ll only need to deal with! I’m curious what size she used on you. I’m sorry that it hurt.
As for sex hurting, it may be because your body is new to it. Or it could be because your exam made you associate penetration with pain, so you may be tensing up.
I couldn’t say whether or not it is vaginismus. But! It doesn’t hurt to dilate! If you’re just becoming sexually active, it may be good for your vagina to get a little physical therapy 🙂 You can already tolerate penetration which is HUGE, so I’m sure you’d ace dilating! I got the Pure Romance dilating kit and I love it! Each dilator is a super fun color and they’re easy to use. If you chose to dilate, you’ll want to do so for 20 minutes a day, as many days of the week as you can. This will help your vagina better adjust to penetration with a penis, or toy.. whatever you fancy! And also, eliminate pain in the future 🙂 Also…. no exam should hurt you. Unless you’ve got an awful rash on the vaginal walls themselves, a speculum exam should definitely NOT make you scream like that.
I hope this helps!!