Sister in law/ stress / ahhh

[Aley009]

Recently I've found things rough, I've been obsessed over my health worries, some days I've just cried over it as I hate feeling like this. I've now started to go off sex. Without sounding crude that's not like me. My sister in law ( partners sister ) has been really rude to me recently she's always been like it tbh but more so since I had ds in December. She just seems to feel she can talk to me how she likes, she commented on a FB pic of my son a week ago saying he's clever and doesn't get his clever ways from me, then made other comments too, my mom & friends of corse defended me but I'm still so angry that she tried to embarrass me Like that so publically. I've been civil since but she still tends to have an attitude making me feel like such a push over! Partner read what she wrote and said he will be having a word, she's 3 days older than me ( I'm 26) I've just found myself now hating the thought of being in her company! When she's okay she's fine! But I'm finding her becoming rude much more frequently.
There's a wedding July 3rd which is their coisens, I majorly don't want to go... I've been with partner 8 years and only recently this is becoming an issue, I thought it was me being sensitive but everyone agrees. But now I've started thinking of it carries on I just want out of his family which is irrational thinking I know.... I'm not sure what I wanted here, Maybe just some Input?