Blindsided by gf after 6 years of a healthy relationship

We were together 6 years , last night she came to me and said we needed to talk. I didnt expect a brakeup whatsoever. We had a great relationship in my eyes,yes it was boring and we didnt do much acitivitys together. But we had a large friend group and always hang out with people and had a great time. She said she was cold for like a year already and had no heart to tell me that. We mostly never fought, little bit of arguing, she was always picking my flaws never complimenting me whick I always found wierd but just thought thats who she is. I just cant belive it because I was 100 percent sure we would get married soon and talked about it often, She says her reasons she saw my more as a friend that a romantic partner , I said that I think a long term relationship look like that its just comes to that with time I dont know. This is so wierd I had like 3 brakeups earlier in life im 31 this year and never thought I would be in this situation again. When we started dating I was so picky to pick her as a right person because she seemed so sweet. I have been always good to her , not the best , but never had any drama or bad situations with me. Thinking now about it, it always seemed like she didnt love because from the beggining she would just always pick out my flaws. I just didnt expect it no one did, our whole friend group is shocked everyone we were so good together.I just had to rant somewhere because I am still in shock cant even plan what to do next with my life I just know a had period is coming