I have experience of emotional abuse and relationships with emotional abusers. I have experience with emotionally abusive family. I have experience of feeling like you described.
It is so hard to explore, accept and progress forward when you are a victim of an emotional abuser.
This man is emotionally abusive. He lies, he manipulates, he treats you like an object that he needs to supply some need for an ego boost or validation. His expression of desire to reconnect is simply for attention and supply. You are an object to be used and he's probably bored.
It is very difficult to see that people can wear masks that we never truly see behind even after years in an intimate relationship with them.
Feeling so useless and desperate as you describe is a fall out of experiences at the hands of an abuser. You would not feel this way if you had been in a relationship that ended with a non abusive male.
I suggest looking online and reading up on abusive coercive dynamics in romantic relationships. I know these are buzzwords but there's a great deal of online advice and speakers / podcasts about narcissistic strong people in relationships. They are unable to love and care for you. It's all a mask that eventually slips.
I watched another online podcast last night. I recall the speaker saying you should be very cautious when people say ' don't you trust me' or ' you need to trust me'. It's a huge red flag and a common behavior by narcissist,/ sociopath behavior leaning people. He's a persistent liar ffs. Trust nothing with this slug. His new improved persona is simply the mask he has put back on to get something's from you or yo just emotionally torment you. Abhorrent and cruel.
The answer here is to explore this possible reality I've suggested to you. Seeking the truth of what's going on here.
Finding validation from others - online or through professionals usually. Gathering your strength and get as far away from this dangerous prick both physically and mentally OP.