Your therapist should not have said that you "should've known better." That's not supportive.

I hope you feel better. if you were with this person for a year, of course its taking time to get over it.

I think you're asking the wrong question. It sounds like its coming from a defeatist place ("will I ever get it right?"). Why not ask "how can I take care of myself during this period of pain?" Or "what do I want in a relationship?" "How can I be kind to myself?"

Take care.