Kevin Costner's 'Friends Are Worried About Him' in Wake of Divorce and 'Horizon' Flop

Kevin Costner is having a tough time . That's according to sources who say that friends of the actor "are worried about him" in the wake of his divorce, and his passion-project film Horizon flopping at the box office.

Life and Style reports that insiders close to Costner have been worried about him being "under extreme pressure," after he recently opened up about developing kidney stones while working on the 2016 movie Hidden Figures . "It's no coincidence he's talking about his kidney stones hell from a few years ago, the source said. "Aside from that, he was a generally healthy guy, but he's not young anymore."

Costner's Horizon: An American Saga - Chapter 1 -- which he directed, co-wrote, co-produced, stars in, and partially funded -- opened in theaters in June, but tragically underperformed. The film's budget is estimated at $50 million, but it's box office revenue was less than $35 million, and it also was not a success with critics either. Due to all this, the source says that Costner "is poised to lose millions," with the "worst-case scenario" being that "he could potentially lose his house."

"He's gone through so much stuff," said the source. "He takes it personally, and these bad reviews sting, though he puts a brave face on. He must pick himself off the floor and reinvent himself while still shelling out money to his ex-wife, [Christine], but the truth is he's not as tough as he seems to be." Horizon: An American Saga - Chapter 2 was schedlued to open in theaters in August, but has since been postponed .

The source went on to note that Costner's love life hasn't gone much better lately, saying that he's "extremely vulnerable" right now, following his messy divorce from Christine Baumgartner, and a rumored romance with singer Jewel Kilcher that has since fizzled out. The insider said that Costner is "not well-suited to being single... no matter what he says."

"All this stress is affecting him and could wreak havoc on him in a physical way," warned the source. "His friends are worried about him and fearing it could all lead to another kidney stone disaster or worse."

Earlier in August, a separate insider claimed that Costner is in "a world of pain," adding, "He's not sleeping well. He's in crisis meetings over his projects. He can't seem to get a hit movie, he can't keep a girlfriend - and his ex seems happier than ever!" The source then exclaimed, "Everything is caving in on him now. It's only a matter of time before he crumbles!"

The report did not note if Costner was feeling any stress over his very public exit from Yellowstone , but it's possible this has been a contributing factor to any alleged pressure the actor might be under. At this time, neither Costner nor any of his reps appear to have addressed the new reports.