I'm so bored with my partner but scared to be without him?

I just seem to get bored in relationships easily. I left my toyboy lover of 3 years for my partner whose 7 years older but I am so bored with our relationship. We've been together for 6 years & have been out together only a handful of times. The pions gone & we seem to have reached a dead end. He's broody but I already have 2 children from another relationship & I'm heading for 40. He initially seemed fun but I've discovered over the years that he's a boring stick in the mud hermit & he has made me feel 100 years old. I miss my toyboy but then have to remember that I left him for a reason. We've never been away together, I love traveling but he always makes excuses so I end up going away with just my children each year. I feel that its well & truly over but I suppose am worried about starting all over again, not being quite so young as when we met. All of my friends have settled down & I'm scared of being left on the shelf