Sir Russel, I wish I had some advice for you, but unfortunately I am struggling with that same question at the moment myself.
When something starts out fabulously, and the goes astray... when do you finally say enough is enough?
A friend of mine just sent me the following quote from an article she read about such decisions (I have no idea of the origin - sorry):
Do you want someone who?
Excites you
Shares your core values, core traits and relationship skills
Makes you laugh
Appreciates your dreams
Respects you
Makes you feel good to be around
Helps you to be a better version of yourself
OR do you want someone who?
Consistently frustrates you
Disrespects your goals and dreams
Does not share core values, core traits and relationship skills
Disrespects you
Tears you down emotionally, leaving you insecure and constantly questioning the relationship
Absorbs who you are and limits your interests, activities and personal growth
My friend is very vanilla.... as is the article.... but it definitely provides food for thought.
Wish I could help... but I strongly believe that everything always works itself out for the best in the end.