I feel like my best friend has distanced herself, am I overreacting?

I've been best friends with this girl for 5-6 years. We've been extremely close like sisters up until recently. Just this year, she started making these shady comments occasionally which she never used to do but I wasn't sure if I was overreacting. Then, more recently, I've noticed her replying to my texts less and less. We used to talk almost every day and called each other pretty often. I am at uni and she's working but she used to take the train to see me at uni. Now, I've invited her up to see me at uni 3 times this year and each time she's said yes, but the day before she had to bail because she's been sick, busy, or something came up. I believe her reasons because she has no reason to lie to me like that and I trust her.

But I haven't actually seen her in 6 months. But I see her out with other people a decent amount on social media. When I text her, she now takes days to respond and I feel something may be a bit off, but I'm not sure if I'm overthinking things. I know she doesn't like when her other friends act distant to her, so I can't imagine she doesn't know we're not as close anymore. Should I just ignore it?
I feel like my best friend has distanced herself, am I overreacting?
Post Opinion