What would it be!?....
Mine would be...
Hello. Hope you're well. Now that years have passed I want to say that with a clear head and with no feelings, I'm so glad we spent those 4 years together, but me ending it was the best, for both of us.... I was so desperate for love and to be loved that I clung onto you when you didn't want to be clung to. I shouldn't have carried on after you cheated but that's on me, I just so wanted to be loved by you.
With all my heart I hope you're happy and with someone who can make you happy.
Your ex.