Devastated after Katie Holmes filed for divorce, this week's issue of PEOPLE examines Tom Cruise's days of turmoil and private struggle. Missing his little girl, Suri, the 50-year-old megastar turns to his inner circle – sisters Lee Anne, Marian, and Cass; son Connor and daughter Isabella; longtime lawyer and friend Bert Fields; his mother, Mary Lee South – and Scientology.

During the final days of shooting the film Oblivion, Cruise managed to maintain his famous composure, soldiering as scheduled. Keeping to himself at times and appearing "stressed," according to an observer, the actor seemed to relax during a visit from Connor, 17, his nephew Cal, and a few other family members. "He said hi to everyone he passed," says a set source. "He was very positive and focused."

It hasn't been easy. After Holmes, 33, stunned him with a divorce filing that led to a settlement just 11 days later, life as Cruise knew it came crashing down in painfully public fashion. Toughest of all has been the separation from his "lovely" daughter, as he fondly described Suri to PEOPLE just before their last visit in Iceland on June 16. "He loves Suri intensely," says a source who knows the former couple, "and he misses his little girl." Cruise and Suri have been talking daily, and on July 17 he flew overnight from L.A. to New York to visit her at last.

Why did it take a full month for father and daughter to reunite? "He's wanted to see her as fast as possible since this started," says the source, citing his obligation to Oblivion as the main obstacle. "He couldn't shut down production, cost people their jobs. People count on him." Having coordinated with Holmes's camp on the visit, the actor planned to take Suri to her usual outings, including gymnastics and art lessons. The two exes "understand that they are going to have to talk to one another for the next many, many years," says the source. "They are going to have to talk, and that's always been his intention – for it to be amicable and to be in his daughter's life." That's Holmes's wish, too. "Katie's immediate concern is for Suri," says another source close to the situation.

With Holmes awarded primary custody and Cruise granted generous visitation rights, "he will have a meaningful relationship with Suri," his longtime lawyer and friend Bert Fields tells PEOPLE. In agreeing to a speedy settlement, "Tom tried his best to do what's right for Suri," says Fields – and not, as some have speculated, because he was trying to prevent leaks about his personal life: "Tom is not hiding anything."

He's not about to conceal his Scientology beliefs either. "Tom is not ashamed of his beliefs and won't hide them from his daughter," says the source who knows the former couple. Despite reports, Holmes has not joined a Catholic congregation in New York, though she has "checked out places where she might be comfortable," says the source close to the situation.

Privately, Cruise has expressed only grief, not anger, over the sudden end of his five-year marriage. "I don't find Tom bitter," says Fields. "He's sad about the situation." Cruise was unaware of Holmes's deep unhappiness until it was too late. At first "he was thinking, 'What did I not see?'" says the source who knows Cruise. But as the news sank in, "he went from that place to figuring out how he's going to care for his daughter."

Cruise is committed – along with Holmes – to ensuring that Suri knows she is still the center of her parents' world. "Tom wants to make sure that she is happy," says the source who knows the former couple, "and knows they both love her."

More on how Tom Cruise is starting a new life as a single dad appears in the 7/30/12 issue of PEOPLE, on newsstands now.

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