I'm thinking of my engagement didn't quite go as planned...
Did you botch up the plan?
Yes, I feel really fucked up about it
That's not a good sign. If you're feeling uncomfortable with the engagement, you have to take a step back deal with what's making you uneasy.
You're right. Thanks for the advice, I'm going to break her heart slowly.
You can always tell her you need more time. If she is that person, she will understand and wait for you till you're ready.