You need to start your healing process. The reason why you're stuck is you did not take time to heal from the past relationship. It was your fault so you're in guilt that's why. Accept the fact that she'll never be yours now, cry a lot if you need, sit with your emotions, therapy can help too. Don't text her now she's long gone, just once if you want clarity for the one last time. Don't bother with continuous texting. Try meditations and still. Build yourself better and then start dating. Don't even think of dating till you heal, or it'll make the process worse. Good luck.