Worried About a Friend's Deen

Me and my best friend are super close. We were both born Muslim and met as teenagers. Alhamdulillah, we actually grew closer to our deen together-it felt like a real blessing because we were both kinda lost before. But lately, they've been having a really tough time with depression and their iman because of some personal trials they're going through. It's honestly stressing me out because I don't want them to stray from the straight path, especially since they mean the world to me. They're still praying and doing the basic acts of worship, but their belief is really shaky right now, and from what I can see, they're only holding on because they feel like there's no other choice. They used to be the one encouraging me to do good, and that doesn't really happen anymore, but it's not like they're pushing me toward anything bad or doing bad things themselves. I know I shouldn't judge or assume, but I'm genuinely scared. Sometimes they say things that really throw me off. Another worry I have is whether it's still good for me to be this close of a friend, or if I might lose that amazing friendship that was built on us trying to get closer to Allah together. Just to add, I struggle with OCD, so I tend to get obsessed and spiral over 'what if' thoughts. I'm trying my hardest to be there for them, encouraging them to keep trying, and I'm making so much dua and putting my trust in Allah, but this pit in my stomach won't go away. They're an amazing person, and I truly love them. Please make dua for them, and any advice would be a big help.