>>I’m still so heartbroken over our breakup
There are 2 ways of handling this:
1) Self-healing – Practice confiding in your God daily, every now and then. Start journaling. A quick 5 min meditation / transcendental meditation will help.
2) Take healing – from a professional – psychologist or a life coach. Take therapy.

>>and it’s really hard to know how easily he moved on from our relationship.
For all we know, it is you who thinks that he has easily moved on. He might be having his own inner battles and suffering from inner chaos.

>>I feel so stuck and want to move on but I’m really having a hard time doing so and seeing him this week feels like such a set back.
Feeling stuck is natural. Karma taught us that we need to be in it for some time until we learn our lessons. So I suggest you give yourself time with patience. Settle in the space and let time and nature take their turn. Seeing him will feel like a setback but let it not bother you. You have much better stuff to focus on – like your career and hobbies.

>>Also he told me that we wants to be friends and I just cannot do that after everything that has happened.
If being friends with him makes you feel like it is pulling you back, then don’t be friends with him. Nothing wrong with not being friends with your ex. It just denotes that you are comfortable on your own and laying the pitch to move forward in life.

>>It’s really hard to let go and move on. I still think about him (more than I want to).
Letting go is the last step. Some cannot really completely let go. Move forward if you cannot move on. Getting thoughts about him or thinking about him is natural. You were in a relationship for so long. Unless you find your purpose in life and derive goals toward it, you will be haunted. Learn to forgive yourself first. I am not at all telling you to forgive him. What he did is wrong. Totally wrong. But you need to stop beating yourself for his mistake.

Learn to spend some time with yourself. Pamper yourself. Hit the spa. Get a massage. Make God your best friend. He is the only one that understands you like no one else. By investing in yourself, you will heal gradually. And you will feel like this relationship was nothing compared to the purpose of your life. This is just a stepping stone. This is not everything.