Never thought id be here

My f36 partner m37 has two children.

Girl 7, boy 5.

We've been together for a little over a year. Things got pretty serious fast, I moved in at about 9 months, and rented my place out. I love him dearly.

I never wanted to be a "stepmum". I thought of my role as more of a fluid "bonus" figure. Here to support but stay in my lane. Here to make lunches, read to them, talk through their problems, but never considered myself in a parent role. I guess I was naive.

I never forced affection with the kids, but over time they warmed up to me and regularly get cuddly etc.

Things are starting to get hard though. My partner gave me the title of step mum (without talking to me about it, or his ex) and kids being kids latched onto it and started announcing to anyone thatd listen that I was their step mum.

Their mum didn't like that and it seems to be causing endless problems.

The kids are telling me their mum says im not their step mum, that's FINE! I never gave myself such a heavy title. I told them they can call me anything they want. But I resent the heck out of it. I never wanted my own kids. I don't have maternal feelings. Im not wired that way. I am a kind person and do my best to vibe with these little weirdos, but all this hate being thrown at me makes me feel like im being performance managed for a job I never applied for. I don't come from a large family. I know fuck all about kids.

Toys I've given them are supposedly wrong somehow. Im apparently causing them anxiety "making" them call me this title. I dont feed them properly according to her.

The pressure is insane. I felt comfortable and thought everything was going well, but now I feel insanely anxious any time the kids are here or her name comes up.

How do I overcome this? Has anyone been through something similar? Non maternal woman who found herself loving a man with two lovely kids who im growing to love? How did it play out? How do I stop this anxiety?

I've asked my partner to not tell me anything she says about me, so I can support him but just not when it comes to her and her feelings about me? As far as I can tell shes a great mum, I have no desire to take "her place", how can I get back to where I was? Let go of this anxiety.

Sorry for rambling, I am not perfect. Im trying. I dont know shit about kids. Im doing my best. My partner says I do amazing with the kids. I don't know why her feelings about me bother me so much.

I don't even know what im asking. I just want to enjoy this nice life with my partner and his kids and.. be allowed to exist.