How do I casually rebuild a friendship I destroyed??

We met 10 years ago as college roommates and became inseparable all throughout throughout college, lived together for 3 years without a single fight, we liked all the same music, had the same interests, and were just always on the same page without needing to say anything. She truly is the closest friend I’ve ever had, and if you’re a girl in your 20’s, you know how difficult it can be to find a girl friend that you truly connect with. Then came the destruction.

A little over 5 years ago, I started a new job at this hotel/nightclub where I was just surrounded by the most sketchy people and involved in situations that were making my anxiety get worse. I was prescribed a medication that didn’t react well with me, and to kindly put it, I lost my fucking mind. I was a paranoid mess and it was truly a psychotic break that I never in a million years thought my brain was capable of. At the time, I had just gotten with my ex (who was the manager of said sketchy nightclub, and surprisingly the most manipulative narcissist I’ve ever met), which my mental state even more chaotic. I freaked out on my friend one day when I was absolutely spiraling and she didn’t deserve any of that, and I still feel awful to this day knowing I hurt her and put her in that position.

We moved into separate apartments after our lease ended and stopped talking. It’s been 5 years and we’ve seen each other a couple times (not anytime recently and never without my ex being there), and we still text on birthdays or when a new season of our favorite show comes out, but it’s never been the same and I don’t blame her for it. I think about her every day and hate how things ended.

Today was her 30th birthday, and I was really sad thinking about how we’re basically strangers at this point.

I sent her this text: “Happy birthday 🥳 I truly can’t believe we celebrated our 21st birthdays together and now we’re gonna be in our thirties :’) I hope you’re doing good and hope you had a fun birthday! If you ever want to get drinks and catch up, I’m always down. I miss you a ton ❤️”

She loved my message and replied, “Tell me about it! It’s honestly insane. Thank you so so much miss you too ❤️❤️❤️”

I’m struggling to get passed the surface level conversations when we text because I don’t want it to feel pushy or make her uncomfortable, but then it just comes across like I’m not interested in hanging out or getting close again. After my ex completely isolated me for 4 years, I struggle with casual conversations in general and I’m so reluctant to get close to new friends, but this is different. I want to rebuild our friendship if she’s open to it, but I never got to fully apologize to her and explain what I was going through. I know a big apology might overwhelm her (she’s not into long, emotional texts). And I’m worried I’ll never get the chance to do it in person because I ‘don’t want to be pushy’ so we’ll just never see each other again. If she’s in a new chapter in her life and isn’t comfortable getting close to me again, I would completely understand. But I don’t want to feel like i just didn’t try when she means so much to me.

How do I reply to her text to keep the conversation going without repeating “miss you” or “let’s hang”? So much time has passed that I don’t know anything about her and just hitting her back with “so, where are you working nowadays?” just feels silly. When I’ve tried to make small talk before, the conversation just dies because that’s not the way we used talked to each other so it doesn’t feel natural, but I just don’t want to keep feeling like strangers. Any advice on rekindling an old friendship after years have passed?

Thanks so much yall, sorry for the long post