"Real Housewives of Beverly Hills" star Kim Richards' ex-husband Monty Brinson has passed away. Brinson died on Sunday Jan. 24 after a long battle with lung cancer, according to Us Weekly. He was 58.

His former brother-in-law Rick Hilton, who is married to Richards' half-sister Kathy, announced the devastating news on Instagram on Sunday night. "We have lost Monty Brinson after a brave battle with cancer," he wrote. "His heart was a big as the moon and he was loved by all he Met. He will be sorely missed. I love You always!"

"Kim is devastated," a source told PeopleBrinson and Richards were married from 1985 to 1988 and welcomed their daughter Brooke, who is now 29, a year after they married. They remained close friends after their divorce, especially in recent years as the 51-year-old reality star has been helping take care of him while he battled cancer.

Just a few months ago, she posted a sweet message to Brinson on his birthday. "Monty...Happy BD. Star light, Star Bright. First star I see every night," she wrote. "Always know your in my heart. I love you so much. We have come so far, let's keep it going. I'm right by your side forever! I wish for you happiness, courage, peace, laughter, love, strength and every you've ever dreamed of!"

Brinson had also been posting to social media recently and keeping his followers updated on his condition. In the days leading up to his death, he shared a sense of optimism with one post of a sign that read, "If you don't believe you won't receive!"

"Even though I'm facing death eye to eye which instead of being scared or put, I'm embracing it as I go forward with this journey. I pray my journey helps others in what lays ahead of them through their struggles," he captioned the photo. "Then it's all worth the pain which y'all make easier on me each day...I got the strength to fight it for all of us and I'm damn well going to try to make your life uplifting if I can...Today is going to be another great day no matter the pain keep throwing it at me I can take it nor will I let it over come my life."

 What a beautiful day January Wednesday the 20th 2016. Yesterday was such a uplifting day which I will be sharing with you later on. It was magical even though I'm facing death eye to eye which instead of being being scared or pity I'm imbracing it as I go forward with this journey. I pray my journey helps others in what lays ahead of them through their struggles. Then it's all worth the pain which y'all make easier on me each day. What if like to accomplish is to take away all your pain and make life easier on yourself. I got the strength to fight it for all of us and I'm damn well going to try to make your life uplifting if if I can. Remember if you don't believe you won't receive, well I BELIEVE. Today is going to be another great day no matter the pain keep throwing it at me I can take it nor will will I let it over come my life. Beautiful day to all as always and much love Monty #believe #love #thankful #blessed #thankful #life #happiness I love life and making people happy. Thank each of y'all for making me happy now go out and smile to make this a brighter world

A photo posted by Monty Brinson (@montybrinson) on Jan 20, 2016 at 10:42am PST