This is going to be a long post with context so TL;DR can't decide if how I'm feeling is because of anxiety or if it's legitimately worth being hurt over. 

Context:
My (F) best friend (M) had been spending a lot of time with this other girl he knows because she needs a lot of help and is leaving for a while next week. I didn't/ don't really have a problem with it, but at times it was tough when it felt like he bailed or didn't pay attention to me but had time to give during the week and every weekend, all weekend, to her. This is someone who says he's fine seeing people once a week or every other week by the way. We also live together but are pretty busy these days during the week. 

Anyways so almost 3 weekends ago he spent a lot of time with me to talk about where he was at in life (he was battling severe depression), what he wanted in my friendship, how he wanted to be intentional with me especially after she leaves, and things about being clear about communication moving forward. I felt like I was really opening up to and trusting him at this point, but since last Thursday he's basically been non-existent. However, she was with him Thursday night- Sunday night and I left for the weekend. But he hasn't responded to any of my texts, including simple things like "hey I brought you some candy back from where I was!" Or "hey I made some french toast, it's in the fridge for you!" 
I find this kind of uncharacteristic of him but my head has been churning with questions like, "he said he wanted to be genuine, so what is this?" "Why this behavior all of the sudden?" "How easy is it to send a simple text saying hey I'm busy I'll catch up on this soon" etc (he has been extremely busy for the whole week). 

I want to be super chill and just be whatever about it, but the historically anxious/ overthinking part of me is still present in my psyche. There's obviously more details but this is the gist. Any tips/suggestions/ advice and just general "hey you're overreacting, just check in on him" ??