Where else to look for work/what other clients to reach out to as a psychology/mental health writer?

I have about 3 years of writing experience; I started at Upwork but currently only have one client from there as no one really offers good pay for articles on mental health topics. I'm trying to get new clients now by reaching out to therapy services and offering to write articles for their blogs and so far I've been successful once. I'm slowly running out of people to contact (in the UK) and websites such as Everyday Health only accept people with credentials (although some of their writers don't even have a relevant degree, just credits from popular magazines). I have a Psychology degree but I'm not a therapist. I'm running out of ideas... as this kind of writer, I'm not sure where else I could look for more opportunities or what other topics I could write about because this is my niche. The only option I can think of is sex and relationships. Someone suggested reaching out to startups as a copywriter but I've never really done copywriting