According to newspaper reports, the soldier-Prince has told friends: "I lost the best thing that ever happened to me and I'm paying for it".
Such is his heartache 24-year-old Harry has even told attractive Gladiators host Caroline Flack that their flirtation, which included an intimate night last weekend in his private apartment in Clarence House, is over.
"Everybody makes it sound like Harry dumped Chelsy and he's having a ball playing the field," a pal told the Sun. "But it is actually the other way around. Harry is taking it quite hard."
Harry split from the pretty Zimbabwean in January after she became frustrated with the constant separations caused by his army career. The law graduate was also said to find coping with the attention of such a public courtship hard.
But the army officer's recent efforts to play the dating game supposedly made him realise just how much he missed his 23 –year-old ex.
Ironically, given the apparent cooling of their relationship, TV beauty Caroline was on the panel that placed Harry at top of a list of 50 men, ahead of rivals such as Twilight star Robert Pattinson, Prison Break's Wentworth Miller and Richard Branson's son Sam.