mail is getting hung up on attachments

Hey all,

My mail program has started acting strangely a few months ago. Instead of being able to find my file to attach, it will either attach my desktop, first folder I went into (the file was 2-3 folders deep and usually a pdf). So of course it is too large. Alternately, when I drag the file to the e-mail, I get the spinning beach ball of death and then I have to force quit mail. I can't go to Catalina since I'm waiting on a program update from a developer or 2. Is there something I can do to make this stop? or do I really need to send it to support?