I think most people know when they're in a toxic relationship - it requires an enormous amount of effort to keep it going, and you don't get what you want from it.
Make a list of all the people in your life, and rate them in terms of energy in, energy out. Is there anyone in your life right now who is blocking your love quest?
One of the things about being online is it's hard to forget people, so it's very easy to stalk an ex, it's very easy to follow what people are doing. It's almost impossible to forget them.