Aaahhh surviving a yandere now, I would start by asking the yandere out using words that would make her believe I'm madly in love with her. This would reduce the risk of my family and friends getting hurt or being killed, I'll even make sure they play along pretending they accept our relationship and don't say or do anything that will get them hurt. This also allows me to dodge the whole possibility of getting kidnap since she wouldn't have a reason to do so. Now that I've gotten into a relationship with them, I would use the power I have over them due to her obsession with me to get her to do things for me starting with therapy and making sure she is more likely to go I would probably say something like if we're going to raise healthy kids in the future will need to make sure we are mental well. If I manage to get them into therapy and keep them going by supporting them, I may have gotten myself a healthy girlfriend. I do have a backup plan just in case it doesn't work but i do have backup plans plus if I have to, I could trick them into turning themselves in.