Mother in laws/ mother in laws to be

Steph
Does anyone else have a struggle and a problem with their mother in laws or partners mum?🙍🏼 
Whatever I do I never seem to be good enough for my partners mum. I don't think anyone will ever meet her expectations. It's actually starting to drive me insane. She's crazy obsessive. She'll text my partner if he doesn't reply she'll text me and then if we both fail to reply because god forbid we are busy she'll text my parents. This drives them insane as they accept us as the 19 year olds almost 20 year olds we are. 
I know we are still young but even the talk of children in the future I get the eyes of death. In a few years time I want to start a family but she's obsessive over that too. She'll be round every day ringing or texting to see what we are doing. I like her don't get me wrong but I need to be able to breathe. The both of us do. To make matters worse I do not get on with my partners father as hes just an awful man who is so rude to me. It isn't like I'm new to the family either. I've been part of it for 4 years. We have spoken to her countless times about this behaviour but nothing seems to be working. My partner has even spoke about changing his number to stop the harassment from his own mother. 
I'm really dreading bringing children into this family as I don't want them to be hounded like we are. I love my partner so dearly but his parents are driving us to dispair. 
Has anyone else experienced this? Sorry for the rant but I needed to vent. The fact she is dictating when and where we have children is just proving too much. We as a couple
Should choose when to have our children and where. Also names should be to do with us and not names which they like and think we should have.