It's funny, I remember reading OP's post like probably a month ago. 
I remember reading the part where if the psychic see's him as too busy or overwhelmed that meant he was with someone else. I remember thinking "Naw that's not true, mines not doing that"
Well consider my surprise when he reached out last week, writing me a letter where he explained why he had to end things. 
Earlier in the year I had what was the best relationship of my life. Calling us soulmates was an understatement
 We were perfect together and so happy. It was only 4 months but it was an intense 4 months. Then one day out of no where he texted me to break it off mid drive on his way to see me. I never got an explanation other then he was too busy and not feeling it? The day before he was literally telling me how much he missed me and couldn't wait to see me. That's when my psychic binge for the second time in my life started lol. 
Fast forward to now. I figured he was being avoidant or maybe just not that into me. Psychics fed me the he's avoidant or he has past baggage he needs to sort through (I guess technically true) but that he would be back and apologize and reconcile.
The letter basically outlined that he left me at the time to go back with his ex partner
 Saying that she was jelous of me so she made some life changes and wanted to try again for their 2 year old daughter. He told me basically he went along with it and a coworker told him to just dump me and not tell me. 
So I guess this has been eating him up inside. The letter was very conflicted and confusing. Saying how much he misses me but also saying he feels he needs to do the "right" thing and stick it out with the ex. 
So when you say they are likely with someone else, I'm here to say that's soooooo true. 
Only Gemini Moon and Phoenix Burning said straight up he was with someone else.
Everyone else mainly said he was stuck on the past and clearing out old baggage from a last relationship (I suppose could be true but so far they are actively together) 
QoC18 was the only realistic one where all her readings made sense and referenced his daughter multiple times. 
Others were close in that with the new information it fits but they never said there was a third party flat out. 
Mattie really disappointed me as she said they would never be involved again - clearly wrong unless there's something I don't know. 
Jury's still out I guess what he will do since his letter made it sound like he wasn't happy with his choice to leave me. Unfortunately I'm stuck making my rounds to see what will happen with this and then I'm hoping to start detaching and moving on. Hopefully leaving psychics in the past because my bank account can't support this habit for long.