Sleep issues - help!

Ava (2) for the past 5 nights has been waking up between 4.30 and 5am hysterical. She screams for us and we leave her for a while and then go into her room and say "Go to sleep" and try to lay her down. She is so hysterical that she tries to cling onto us to get out of bed and she shakes. After about 40mins and 4-5 times of going into her room and trying to settle her, we take her into our room.

I don't know what is wrong. She had grommets in last week and then my partner went away for work (when this all started) but he is back and she is still doing it. I took her to the Dr the other day and one of her ears is still infected but nothing like they used to be.

I don't know what to do or why this has started. I am starting to lose the plot having to get up so early and i hate seeing her that way .

I was going to suggest nightmares as well. Or is it possibly night terrors (never experieinced them so not 100% sure).
Could it possibly be a result of the experieince of having the grommets put in? Not the grommets themselves but any pain she experienced before/after, the experience of going to the doctors etc? Jack had his leg in plaster when he was about 2.5yrs and he all of a sudden became very clingy. These sorts of things effect them in all sorts of ways

DS does this sometimes, no idea what it is, could be night terrors... anyway, we find sometimes that a cuddle works but sometimes the best thing is to just leave him and he will sort himself out. Seems awful to leave him when he is so worked up, but sometimes continuing to go in to try calm him agitates him even more if that makes sense?