I can understand your frustration. I was in a similar situation and had a hard time trying to find the right partner. It's funny that you mention
PartnerUp, since that is where I ended up finding my business partner.
They used me as kind of a little case study over at
Business Pundit.
My suggestion would be to have a lot of patience and to do everything that you can think of to network with absolutely anyone and everyone that you know. You never know who might end up being the perfect business partner.