Did I really lose her? Is there anything I could do now to make the situation any better?
First of all, let me say thank you very much for asking this question and for taking some time to do it, I really appreciate your big effort. Also, let me say that I am truly sorry for your current painful situation, I can see you are very hurt because of this. I can only imagine how hard it has been for you during the last couple of months.
Regarding your question about what could you do now, I honestly think that the best you can do is give her the space she is needing and asking for. Doing the opposite won't allow you to achieve anything further, while maybe with some space she can reconsider the current situation and, eventually, come back to you.
Also, while letting her have some space, you can take advantage to do the other main thing that I recommend doing in this particular situation: taking some time to focus more on yourself and your needs. Sometimes, we put too much attention on other people and we don't focus on having a better relationship with ourselves. Why do I recommend this? First, because this is going to be very positive and healing for you and, second, because the more you put attention on her the worse you are going to be able to stand the current situation. If you react to your sadness - seeking for what you have lost - you won't get over it; while if you focus more on yourself and the things you want in life, you will be 100% able to move on and, as I said before, perhaps in the future you will have another chance to be again with her.
Finally, I want to say to you that, even if this looks very tough and impossible to pass over, you need to remember that you will be able to do it and that these hard experiences, when you face them being authentic, they make you grow as a person. It's only a matter of time before you feel better, so try to see your pain with a bit of perspective knowing that you have gone through the worst part and you succeeded.
I wish you the best from the bottom of my heart. I know this hard time will go and you will achieve your purposes. Good luck.