Friend or Foe

I'm worried about making new friendships in my thirties. My best friend and I have been friends since we were thirteen. My right hand gal pal that I met in college has been my friend for sixteen years now. My recent friendships don't feel sturdy. I met a new friend five years ago and my ex didn't like her. I thought she was sweet and a bit sad. I felt bad for her. Turns out he may have been right about a few things. I don't think I know how to do this anymore or maybe I just don't want to do this anymore (sidenote this is also my issue with dating in my thirties.) It was easy when all we had to do was like each other's clothes or the same boys. Now I can't just let strangers into my life. I need to know their intentions. I need to know why they want to be my friend. Is this friendship purposeful? Is this friendship healthy and godly? Will I have to block you? I'm annoyed and it makes me want to shutdown. It's my default defense mechanism. The Bible says if you want friends then be friendly. Maybe the entire problem here is me