<human>: There were no fights, no warning signs, and no issues communicated between us leading up to the breakup. We just had a really good 2 days together. (We had summer plans. We had sex. Etc. It was smooth sailing as usual) 

We never really fought in 4 years but we did talk about things when there was any issues - only now I realize that she had a couple concerns brewing under the surface. 

Our relationship was very strong overall and we shared a love and appreciation for each other with the shared goal of becoming engaged in a few years, and later getting married and having a family.

Then everything ended abruptly when she stopped by and told me we were breaking up. It felt so harsh and sudden. I was in shock, and even now it is still sinking in a few days later. She gave a few vague reasons as to why, which I didn't fully understand but I'm reflecting and I think I'm gaining clarity. She had been questioning things for a week or so and decided the night before, without ever expressing it to me. I feel we could have worked past her concerns or at least tried to. 

My emotions are all over the place all at once. I don't know what to do. There's so much I want to say that I wasn't able to say at the time because I was caught so off guard by it all. But we haven't contacted each other since. I want to know she's alright. 

What should I do folks? We were in love and best friends and now we are going to be nothing just like that? Is this kind of breakup normal? (Not saying it's easy to breakup with someone but it just seemed so sudden and cold.)

Can you condense the text into three sentences or less?
<bot>: Great 4 year relationship was ended abruptly with no communication of any of her doubts. I don't know what to do now.