Answer
Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
Though you don’t have any legal proof for it, indeed, this person has wronged you by keeping you waiting all this time and finally by breaching his promise.
From your part, you should start a new life, in spite of the negative influences of this experience. You should make a lot of du`aa’ (supplication) to Allah and sure that He will grant you all what you ask from Him.
In his response to your question, Sheikh Ahmad Kutty, a senior lecturer and an Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states,
This guy is indeed guilty of a most serious offence; he has betrayed your trust by keeping you waiting and then has broken his marriage promise. This undoubtedly is a grave offence.
Now that he is married, you should close this chapter and plan for your future. You need to turn to Allah for solace and comfort. Allah is certainly with those who return to Him.
I would advise you to get a copy of Invocation of God by Ibn al-Qayyim al-Jawziyyah. Study it and practice the lessons. It will help you overcome this trial.
For more, see these fatwas:
What Invalidates Marriage in Islam
How Islam Views Early Marriage
Love before Marriage in Islam: Accepted?
Can a Muslim Woman Perform a Marriage Contract?
Allah Almighty knows best.