I’m so sorry. These situations really suck. Honestly I think what really hurts is that the love and respect you were giving wasn’t reciprocated, and in fact you were treated with disrespect and carelessness, that someone you cared about didn’t care about you.
I think the best thing you can do is focus on yourself for the moment, and learn from this. Set your standards higher and do not allow people to treat you in a way you don’t like. Next time, don’t wait. Take the their non decision as a “no”, immediately. If someone wants a relationship with you they will put in the work to make that happen, if that’s not happening then they don’t want it. So move on. And that’s not a reflection on you, they’re just not the right person for you and that’s okay.
Don’t worry about how long you’ll feel like this, just focus on right now. Personally I find journaling and writing down how I feel, what I feel I could have done better, what I feel they could have done better, what I think of the situation now I’m out of it, what I’ve learned that I want more of and less of from a romantic partner, what things I now know I need from and what I wouldn’t tolerate from my next partner, etc etc
Just put out all your thoughts on paper when they feel overwhelming.
Right now, look after yourself. Date yourself. Treat yourself to a coffee date, get your nails done, run yourself a nice bath, whatever. Spend time with your friends and family. You will be okay ❤️