Op I'm finding chatting really useful. I have considered telling my mum about our ivf. A friend and the counsellor I'm seeing now have also suggest, that it could be healing, bonding etc.
But hearing your description of your mums reaction to you eptopic sounds so very familiar. I just know she'd react that way too.
One thing I do try to do is play up the things we do bond over. So one of my mums narratives is that life is always very stressful and difficult. I actually love the balance we have, me working 4 days etc. But mum assumes that's all very stressful and tough. Sometimes I can get her to disinvite or say no to herself by playing up to that. (Though she's also get jealous if, say, I cancel a visit because DD is ill).
She is also my no 1 place to vent and bitch about Dhs parents (who have a different set of control issues). She LOVES that, laps it up, can Rasputin ever self she's the better GP. And I get to get it all off my chest!
So she feels like I do confide in her on some things, and she can support etc. She needs to be needed. So I try to pick and choose the things that work for me so she's can feel good about them.
You mentioned the affect on your ds. I don't think you need to worry. You'll be much more influential in his life. As he gets older you can be honest with him on some of these dynamics in a age appropriate way. PIL try to manipulate DD outrageously and already she is not having it. It's quite funny to watch. And it doesn't build the close relationship, rather makes her distance herself, but that's their problem.
I did a therapy workshop for myself a while ago when DD was about 18 months. Everyone there was dealing with issues for their parents. Mostly their mothers. I spoke to the therapist about it and asked her advice, saying that as the mother of a young child it was sad to see how wrong it could go, and did she have any advice for plotting a better course. Her reply was 'the best advice I can give you is to work on yourself, and resolve your own issues as best you can. Trouble comes when you don't, the issues don't go away, they get perpetuated.'
I think it's true that the biggest issues with DD are usually not about her, so much as me and my reaction. So I work at examining myself, when things are hard, to figure out what it's triggering in me and what I need to change in myself.
Many in the generation of our mothers have never done this, or would dream to. And they've lived through a time of enormous societal change, where the rules and expectations have changed a lot.
But we can break that cycle.
Have you ever had any therapy? Might be worth considering to help you get to a better place with some of this stuff...