Jon Gosselin minus his kids equals heartache. The onetime Jon & Kate Plus 8 star, 38, exclusively tells Us only half of the eight children he shares with ex-wife Kate, 40, visit him. “I’m upset,” says Jon, now a nightclub DJ. “I’m hurting.” Twins Cara and Mady, 15, and two of his 11-year-old sextuplets, Collin and Alexis, refuse to join Joel, Aaden, Leah and Hannah when they visit Dad on weekends at his Reading, Pennsylvania, home. Jon, who has partial custody, plans to seek joint custody when he can gather the funds. Meanwhile, to see his estranged children, he watches clips of the TLC show Kate Plus 8. Otherwise, “I don’t know what they look like.” HE SAYS/SHE SAYS The former IT manager, who is dating nurse Colleen Conrad, 45,…
