Thanks for your responses everyone. I went to the GP today and she was SO supportive and validating. After getting my work and educational history and current concerns etc she told me that just last week all the GPs in their center had a professional development workshop about ADHD in both children and adults, and she absolutely agreed that further evaluation was warranted. I was really, really worried that she would invalidate my concerns, so that was such a relief to me. She told me that prior to the prof. dev. last week she knew very very little about ADHD, particularly in adults. I'm so glad now that I did 'forget' to get an appointment for the last three months!!
I should have contact from the agency I've been referred to within the next two weeks. The sooner the better, I say.