At least you tried

Sometimes people are just oblivious. I don’t think she meant anything by it

your friend checked out of the friendship! confront her with your concerns and make her do the same... something good MAY come up from that!

So she was distant after some times you were distant... don't assume this means anything more than your own mistakes did. Give her the extra chances you want her to give you. Maybe openly discuss all of it, like say "I feel like we're not as close as I want & I know it is largely my fault for prioritizing xyz lately, but I want to make 'us' more of a priority. Does that sound good to you?" Possibly she was using her phone to calm anxiety (like a stress ball or other fidget device) or was texting with someone having a crisis, or something else understandable, rather than using it for entertainment because you bore her or anything else offensive. May be an FML but it may be an easily dealt with misunderstanding. Don't assume the worst quite yet.