Please help me cope.

Hi, My mother had a seizure a few months ago. She hasnt had once since but she did have one when I was about six (Im 18 now) with no seizures in between. So, its a very rare thing for her. Both were un-diagnosed but more than likely due to her high blood pressure. We now have her blood pressure under control and shes taking seizure medication. But Im still terrified. When she had the one a few months ago, I just happened to come out from my room to find her on the couch during it. Thank god my nurse uncle was staying with us at the time because I was petrified. And I have never been good in those situations. But now Im in a constant state of anxiety. I cant leave her alone. I sit at home all day even when my friends want to go out. If Im at work I text her constantly to check up on her. I never go to bed before she does. Even in the shower I call out her name just to hear her respond. She is very obviously annoyed by all this but I cant help it. Im so scared Ill walk into the room shes in and see her having a seizure. Or worse. I am honestly on the brink of sanity. I live in constant anxiety and paranoia. So why Im here is to ask for any advice to cope with this?