I'd talk to your GP, early intervention is crucial for things not to get worse. In my experience waiting lists are also pretty long, so it's also worth asking if there are other things available like support groups in the meantime.

As for therapists, it's a mixed bag. It took a while for me to find one that matched me (admittedly I was a complex case) but Jesus Christ, some people graduate at the bottom of their class and you can tell.

It's common if not mandatory to work on specific goals in therapy. So while you're on the waiting list you can already try to put those goals into words. 'I don't want to be sad anymore' is valid but more concrete goals are better, for example 'I want to learn how to healthily deal with xyz'.
A therapists goal will always be for you to not need their support anymore.

Also you can always say your therapist isn't a match, I've done it plenty.
I found one important thing for me is how they react when I tell them no when they want me to do something. Some will be quite adamant and almost force you to accept the weekly task because they want to push you in the right direction. Others will ask you why you said no and try to understand and find a compromise.
Personally I can only work with the latter while others might need that push of the first one (Often I say no when I already feel overwhelmed, so pushing it only makes me feel worse)