Do I stay or do I go

I have been with Susan for many years. I would say for the most part we got along great. We have great times sitting at home listening to music watching tv, etc. She has been pushing the issue of getting married now for a long time. I tell her that I do love her but I am not wanting to get married right now. I have been faithful to this lady. We got in a fight at a function we had attended and have really not talked since. She gets very jeolous and insecure if I stop and talk to another female. These are people I have known for over 30 years. I am afraid to say hi to them because of what this causes. Long story she left the hotel room and went home. This problem will always be around should we stay together. When we are alone things are usually great. What do I do? I do miss what we had and do love this woman