Is it normal that i overthink everything i say to my friend?

Do I know you?

I have the same problem. It's like I choose my words way too carefully. I think for me it comes from when I was young I got introuble and pissed a lot of people off when I talked because I'd always say the wrong thing.

frantic effort to avoid abandonment, symptom of bpd

Yes. I second the Social Anxiety. It doesn't help that you appear to have a history of it going wrong leaving you with a learned behavior from prior trauma.
Depending on the rapport level you have? You could admit to them that you have social anxiety and feel as you do. I've been that friend to someone. And in his case it came with the admission of:
"Everyone hates me. Everyone leaves me. No one understands me."
And it was because he had no social cues. He didn't know how to read a room. Or have a filter. Or the like. I would recommend that you look into a treatment manual at the very least for the anxiety. While also looking into more understanding of how to read social cues and move with the flow of conversation.
And no, I don't have advice on that last part. I'm not that great at hiding the truism that in the end? We're all just waiting for our turn to talk.
That's part of why Text is at points safer. There's less waiting to get to - The Point.
And it's easier for both parties to keep track of something with line by line edits, recalls, and the like.
So yes, you're normal for what's wrong. You can make it right with time, self-love, and guided introspection.

Social anxiety. Seen it!