sounds like you and your friend have grown apart. i know this must make you feel sad but soemtimes this happens, locust. i guess you have to ask yourself now what's keeping you in the friendship. do you enjoy being with your friend when you are with her?
one thing you could do is sit down with her and tell her how much you value your firendship, that u miss the time together, and ask her what's going on. she may or may not give you a reply that explains all this that's been going on with you two. another approach would be to seek out new friends that you do enjoy.
hope this gets worked out. it sounds like you would really like to continue the friendship but idk if that will work out or not. my best wishes to you.