Depression gone....and I'm left with a different girlfriend

I've been with my girlfriend for 5 years now but we are best friends since we met in college 10 years ago. Every bit of it has been wonderful. She has been the closest person in my life and we have been through a lot together. She's always been there for me through tough times. Since I've met her she's always been battling low level depression in some form and I've always been there for her and encouraged her and helped her and wished so much it would improve for her.

Well it has! She is in the best form I've ever seen her in and that is wonderful... but she's not the same person at all. While we are still together and have a laugh and have good sex, the tenderness, the sensitivity, the gentleness, the personality traits I love about her seem to all be gone and with them so is our "connection". It's not down to any new medication or anything. Maybe it's her falling out of love with me, maybe she's met someone else, I don't even know. From friends who tell each other everything I'm now her pitstop on the way to something else and she's always very "busy" with her stuff now, busy tidying, busy chatting on fb, busy and always distracted so conversation has become very superficial. I'm now an obligation and shes grateful when I say "hey don't bother coming over if you're busy". I feel like the only place we connect is through sex and that's becoming not enough for me.

I'm honestly happy to see her happy but I'm also really lonely in her company and I feel obliged to hold back from any proper personal conversation about myself because she can kind of ignore it, shes so busy and then so tired when we do come together. She's talking about our future still, I don't think she is thinking of breaking up right now at all.

I don't know exactly how to bring it up for the best. I feel like it'll sound like I resent her improvement or that I'm saying "hey give me more of you, love me like you used to though you obviously don't". It feels like a massive shift in just a few months. I'm not really sure how to handle things for the best. It's such a big change in personality. Has anyone else been through anything similar and what did you do? Do I force the issue and make demands for her time and affection, even interest, or do I ride it out and see where it goes because she deserves to feel happy and well and I don't want to be a downer on her? Or are these the signs that it's just over?