Like the title suggested.
I care deeply about this friend and as expected her dating history isn't great.

She does not know this guy, they were never friends and met 3 months ago at most.

She was literally dating someone else 3 months ago!! And that guy was trash so she already needed time to recover.

I was happy when she told me she got in a relationship and he treats her right, I really was..

Fast forward TWO BLOODY WEEKS and they're ENGAGED.

she called me and made him tell me himself and I understandably was quite literally stuttering on the phone and went " w..what...b..but...how?!  Why?! " 

This guy didn't even have any answers he said he did it because he could and I can hear her in the background laughing.

I expressed my concerns in our group chat (she didn't respond) and I got my other friend telling me to just be a "good friend" and be happy for her.

I'm absolutely terrified for her!!!

In our culture the groom would come and ask for the family's permission to get married and my guy is doing it in FEW WEEKS. 

they aren't even planning to be engaged for that long!!!

Please tell me I'm not going crazy!!!

I have the disorder, I know how impulsive it can make you feel but this is beyond anything I've ever experienced.

Help..