Affiliate Marketing Secrets

Why is it so hard to start an online business? All I want to do is work for myself, generate income for my family, and work from home. Of course I would LOVE to make millions of dollars, BUT, I would be 100% happy just making a decent income working from home while keeping my kids with me. Can someone help me? I don’t want or need any scammy advice, just real, honest help. I’ve been trying for 4 years to start something and nothing seems to work, or it makes me a little money and then stops. I know how to create my own website, I know about social marketing (or at least enough I think), I know a fair amount about SEO, but I think maybe I just can’t find the right niche? I also can’t seem to get my websites out there enough, so I obviously don’t know enough! HELP!!