"You replaced me already?"
If she has been acting cold for a while, it's probably because she has already been getting in touch with other men, exploring her options in a soft way (that doesn't involve cheating) or even worse. In any case, you shouldn't ask something like that, never. I don't know if you asked in a insecure way (it's alright if you did, we are all here to learn and be better), but no matter if she did have or not, she would never let you know.
It's a complicated situation and I'm sure that if you had feelings for her (or still have) you are suffering right now. I understand you because I have been in the very same situation as you are right now a couple of years ago, but I let my fear take control and ran after the woman - who I thought was the one, just to end up disrespecting myself and killing the little respect she had left for me. Gladly, you are now in our community, so our fellow gentlemen can surely give you tons of advices on how to proceed from now on.
What I recommend, which I think it's the best way - either if you want her back or just to heal yourself, is to cut all contact. No need to block her (tho I think it would be a good idea, judging the fact that she broke up with you via text), but delete her number at least. If you have her on social media, unfriend and unfollow. From now on she doesn't exist. Every call she gives you (she probably will between the end of the first month that you don't contact her and the beginning of the second one) you won't accept, and every text she sends you won't reply. I know it's something hard to do, so instead of killing yourself with anxiety it's much better to just delete her texts right after she send them to you. Now judging that you can have some physical contact, I'd recommend you to not say anything to her. If she comes to talk with you, be short, do not talk. Say you have something to do.
The idea is that women can guarantee their way to act on you when they know your thoughts. They know your thoughts by what you tell them. So if you are not telling her anything, she doesn't know what's going on. Are you grieving? Are you having the time of your life? Did you replace her? Did you already have someone on her back to be with? She won't be able to stop thinking about you. Women need that validation that she did the right thing by dumping you, and the only way (or the easiest, even if it's pretty hard) to not give it to her is by not talking to her.
Now, live your life. This after breakup time is good for motivation. Go to gym, start a diet, focus on your projects, save money for having a trip. Now it's your time.
Stay strong.
