You need to actively start reaching out to prospective businesses. Here, on linkedin, on AngelList, by emailing them directly, etc. Or hire a salesperson to do it for you. Although I don't know if the fees aren't going to be too high even for most high-risk businesses, especially if they don't include cryptocurrency network fees. Cryptocurrency casinos, for example, often have house edge around 1%. If I were you I'd probably start with contacting instant exchangers first.
I'm not sure I understand your request. You're looking for a payment processor that is willing to accept casino, forex, etc. related transactions? If so, then I don't think there is a better alternative than running your own node and coding your own thing. I don't think a traditional payment processor is ideal for what you're trying to do.
OP has his own payment gateway and is looking for customers to whom he would offer his services. CPC and CPM he mentioned means he paid for some ads which failed to yield success.
