You and I both went through this at about the same time. My loss may have been a little easier as the horse was being retired in any case and I had already started looking. Losing him, however, was a huge shock and not a day goes by still I don't think of him.
I went ahead with my search and found a new partner, one who desperately wanted consistent interaction and had an owner who understood that. He is a love bug and our bond grows deeper each day.
I had the same feelings when I continued with the search...betraying Paddy's memory, feeling guilty. I talked to several people who knew the situation, including people from my barn, and all encouraged me to follow my heart and do what I needed to do to heal.
As my barn manager put it, there are many horses out there who need someone to care about and for them in their own special ways. If a horse comes into your life that you can't stop thinking about, then there is a reason you found each other. When I found Rigo's ad it had bare information and no pic or vid but something kept me going back to it. I waited a few days prior to calling as sort of a "why not" gesture not really believing he would be the horse I was looking for; it was just a horse to go see.
It could be Chinga is sending you a message. "I'm OK mom...time to move on."