Anyone but me constantly scared that Regina is gonna go back to her evil days again?

Every episode since the start of the season, i've constantly been afraid that something is gonna cause Regina to snap and make her the villain again. I think it's partly cause when Regina seems to have changed when she was helping David with contacting Snow and Emma when they were in the enchanted forest while dealing with Cora, I was hoping she has become a good guy then but when Snow and Emma came back as did Cora, Regina became the enemy again so I'm just really afraid that either Zelena or some other evil villain is gonna convince her to join the dark side again. This might sound weird but I'm actually hoping that if it does happen, it's cause she's been brainwashed or something instead of it being totally up to her. I love seeing evil Regina but it's been nice seeing her help the hereos and be joining in on the angry glares the hereos give the villains. Plus, if she remains good, she's more likely to get her happy ending which is what all us evil regals want. :)