You really want to know what the truth is?
The truth is, you experienced Love, and it's over now. Yes, it's clique and hurtful and feels like the pain will never end. But it does, it takes some time, but it does goes away. I think you're young. Getting rejected by text has got to be the worst and I'm sorry that happened.
I think you're being rather hard on yourself when you say you didn't deserve her and was a bad boyfriend. The purpose of dating is to see whether compatibility can extend into the future. You found out that this particular relationship won't last. Instead of dwelling on the negative, focus on the positive. You seem to be reflective on your actions to contribute to the end of the relationship.
It also seems you're making excuses for her poor judgement and actions. Seriously, breaking up by text? That's just immature and shows lack of communication skills that she couldn't face you directly to end a relationship. Continuing to use you as a fwb even though she knew you felt much more for her shows her indifference to you.
This was your first real Love. There's going to be many, many others in your lifetime. So don't sweat it. Put away the pictures, tuck the memories in and go live your life in the best way possible for you. Let go of the past and embrace the future. Vow to focus on your education, getting a job, go volunteer, take up a new hobby.
In your closing, you referred to a third chance. Make the third attempt to focusing on being a better you. Take time out of dating to find who you are and give yourself that chance. You won't regret the time.