How do I move on with my life after this relationship?

Appreciate you sharing and great question.  There are many emotional stages and ties when moving forward from a relationship especially when you may/or may not have wanted it to end.  First it's very important to "feel" your emotions and feelings related to the break up.  Many times emotions can be all over the place causing pain, and at times confusion.  Take it easy on yourself.  Allow yourself to really feel and be present in those emotions when they are happening.  It will help you to process, heal, and move forward.  Trying to ignore those emotions and or feelings will only delay your healing process.  Be truthful and authentic to yourself. 

Sometimes we linger on the "whys?" in a failed relationship.  To be quite honest you may never get the answers.  Don't put a huge focus on getting closure in failed relationships.  Waiting around or even expecting an apology can exhaust you, and in some cases it never comes.  The closure you need comes from the work you do on yourself, it won't always come from your ex. 

Amidst this difficult time, really lean on your support system.  Link with and pull together your support system.  Surround yourself with friends and family who want the best for you and are willing to support you.  Lean on them when you're feeling really low and lonely, reach out to them when you need to feel supported and uplifted.  A huge piece that is very beneficial when going through a breakup is talk, talk, talk.  Don't be afraid to share you experience with others.  If you find that difficult, try journaling.

Consider getting a therapist, sharing your story and experience is important.  Not only does it help you process what you've been through but it helps when you can get different perspectives of your situation.  Focus on you! When you leave a relationship, parts of you may feel lost.  Get back to you.  Prioritize your happiness and really utilize this time to re-discover yourself. This can be a very fun and awakening experience.  While doing this, really focus on self care and building healthy habits for yourself.  Things like exercise, reading, meditation, massage, or even binge watching television are all forms of self care.  Self care not only feels good it's a great way to build healthy habits for yourself. 

Another key piece to moving forward with a break up is taking a break from communication with your ex. Remember be the bigger person even when trying times warrants your anger.  Ignore things such as "putting your name through the mud" and keep your focus on a healthy situation. 

Finally another thing to keep in mind is not to blame yourself. It's never your fault if someone treats you poorly.  Learn not to blame yourself, forgive yourself where you see fit and move forward with no guilt.  Hope this helps.