Convertible Note Issue: angel investor wants board seat

I'm in a difficult situation and trying to figure out my next steps.

angel investor wants board seat. I've been dealing with this for about 11 weeks now and the situation isn't improving.

I have already consulted briefly with a lawyer but the other party is not cooperating.

Should I hire a lawyer for this or try to handle it myself?

Went through something like this -- ended up getting a lawyer involved which made all the difference.