For monthslong stretches in 2015, Daniel Rivera spent entire days inside his trailer with little to no sleep, unaware he was in the middle of a manic episode stemming from his undiagnosed bipolar disorder.

The condition cost him his job as a manager at a local Cinnabon, and he had no health insurance. So he endured the vicious cycle of insomnia, euphoria and fatigue to the point where Rivera also lost his savings and the home he lived in for a decade after getting evicted from his trailer park.

He spent the following months living in his car, confused about his symptoms and spiraling into a “deep depression.” For nearly six years, he rented a small storage shed in the backyard of a Vallejo home. The shed was in terrible condition and not meant for someone to live inside. But, at $300 a month, it was what he could afford in the city he grew up in and had never left.

Seven years after his eviction, Rivera is on more stable footing.

 ‘I can’t focus on my mental health, I can’t go and see a therapist or any of that when I’m constantly worried about where I’m going to sleep tonight.

Rivera is in a recovery program and three years sober from marijuana, which he used to cope with his depression and bipolar disorder. And he’s now able to focus more on his mental health after moving into a single-bedroom apartment in Vacaville this summer with the help of The Chronicle’s Season of Sharing Fund.

The Season of Sharing Fund works throughout the year to prevent homelessness and hunger in the nine-county Bay Area. All donations directly help people in need, with administrative costs covered by The Chronicle and Evelyn and Walter Haas Jr. Fund.

Daniel Rivera checks on a motorcycle passed down to him from his father as it sits outside of his new apartment in Vacaville, Calif. Tuesday, Oct. 18, 2022. After decades of living in unstable or in-between housing, Rivera now lives comfortably in his own apartment in Vacaville.Jessica Christian / The Chronicle

Rivera had to pay $3,000 to secure his apartment, and the Season of Sharing Fund is “one of the only programs that we have here in Solano County that cover deposits,” said Zaire Persley-Hurt, Rivera’s case manager.

Persley-Hurt, a case manager at the Vacaville Police Department’s Family Resource Center, said the need for programs such as Season of Sharing has skyrocketed since rents have gone up “tremendously” throughout the pandemic.

Deposits for an apartment, which in Solano County can cost up to $10,000 based on credit history, are one of the main barriers to escaping homelessness and addressing personal health, Persley-Hurt said.

“Here’s the thing — you can’t work on your mental health or your physical health or other issues if you don’t have stable housing,” she said. “I have several clients who are homeless or unhoused, and they’re constantly saying, ‘I can’t focus on my mental health, I can’t go and see a therapist or any of that when I’m constantly worried about where I’m going to sleep tonight.’”

Rivera was living in the shed when he got his bipolar diagnosis in 2019.

His living conditions made it difficult to focus on his mental health.

The 9.5-feet-by-10-feet shed owned by “a very toxic” landlord was only big enough for a bed, mini fridge and a few essential belongings, Rivera said. Rodents infested the shed throughout the years and would eat Rivera’s food. The flooring was uneven and made of wood panels. Termites ate at the walls.

Though the shed had electricity, it didn’t have any running water. The landlord, who lived in the property’s home, placed strict limits on how and when Rivera could use the home’s kitchen and restroom.

“I was living in this place that was really bad,” Rivera said. “At least it was a roof over my head.”

By the time Rivera moved out of the Vallejo shed, he was paying $450 a month in rent, reflecting a $150 increase in the initial rent. A storage fee for the motorcycle Rivera had inherited from his dad, whom Rivera cared for before he died of cancer, bumped up the monthly rent. Rivera’s landlord raised the rent again by $75 a month for shoddy “floor repairs,” Rivera said.

The first time he walked through his apartment in June, Rivera became overwhelmed with relief, happiness and “a sense of freedom,” he said.

Rivera secured a Section 8 voucher earlier this year but found it “extremely difficult” to find an affordable place to live. An apartment complex in southwest Vacaville accepted his application after he’d spent nearly four months searching.

A friend in Rivera’s recovery program steered him to the nonprofit Resource Connect Solano, which connected him with Persley-Hurt. Season of Sharing and a local church helped cover most of the deposit. Rivera used some of his savings to pay the remaining $200.

The first time he walked through his apartment in June, Rivera became overwhelmed with relief, happiness and “a sense of freedom,” he said.

The kitchen and living room offered ample space for his food and belongings. The restroom was his, meaning he no longer has to keep his toiletries in a plastic bag, like he did in the shed.

Four months after moving in, Rivera is still working on filling out the place with furniture. But with a place of his own, he’s now able to do what he couldn’t over the past seven years: Prioritize his health and recovery.

“That freedom is just a great feeling to be able to have,” Rivera said.

Ricardo Cano is a San Francisco Chronicle staff writer. Email: ricardo.cano@sfchronicle.com Twitter: @ByRicardoCano