I can tell you that most people do get frustrated with trying to lucid dream at some point or another, because usually no matter how often you have them, it isn't enough. When you say regularly have lucid dream, you need to be more specific, because it depends a lot depending on what you consider regular is. Some people would consider one a month to be regular, while others might say once a week. And some people can have a bunch in a row, and it seems like they are having one every few days but then suddenly they have a dry spell and don't have one for a couple months. Then even peoples definition of a lucid dream can change, as there is a lot of gray area involving semi lucid dreams.

I would try giving dream signs another chance. Keep in mind that it doesn't have to be a pattern you see every dream. If you see something repeat once a month that works fine as well. Maybe think about old homes you lived in or old schools, any place you spent a lot of time but no longer see. That seems to be a fairly common theme, to dream of places you know very well.