Established site -- Should I Introduce Affiliate Products?

I run a site that's a hybrid of a design/development blog, and a subscription service where I sell premium video courses.

Right now, about 80% of my traffic comes from Google. I started at the beginning of 2017 and grew it to a site that receives around 10k-11k visitors daily.

I monetize it via the following methods:

1. The $9 monthly course subscription service
2. Adsense on the free articles/tutorials/courses that I write/record.
3. Youtube (I have a 155k subscriber yt channel that has been around for years)
4. Udemy (I upload my paid courses there as well).

The problem I'm facing is this:
Being that I'm a 1 man show (I handle all design/dev of the site, marketing, writing and recording tutorials/courses, etc..) -- I only have so much time to dedicate towards producing courses for premium members.

Being a course instructor, I recognize that I'm not the only quality source to learn design/dev. Udemy, Pluralsight, LinkedIn Learning (Lynda), Skillshare -- all of these networks offer affiliate programs that I can potentially make decent money from. I can't figure out how to integrate affiliate products within my current structure, especially as I have my own subscription service.

I also worry about negative side effects SEO-wise for introducing affiliate marketing products, though, I admit I haven't researched this much.

I also have a 50k email list that I could market to.

I'm just curious if anyone has some solid ideas to work through the problems I'm facing. ATM, I can't afford to hire course instructors who are quality enough, as the going rate seems to be $2k-$4k per course, which would eat through most of my profits.

Thanks.