Lemme give you an idea why things aren't always clearcut "you can do
that so offer it as a service" type thing. Here is my site Mind-mojo.com. I spent weeks on that, and months (too many to count) doing the graphics for my product (the license to them cost me nearly $1000). I adored designing the covers and if I do say so myself, they aren't half bad. Offer to do graphics for others you might say (yeah I can do banners and ebooks etc). Ah....it can take me a good day or two fiddling and farting around, I can't just knock them up in a couple of hours. The rates people charge - especially on Fiverr - wouldn't be viable. I wrote the articles on the site. Not brilliant - though I do think the Phantom Pregnancy one is cool

- but I can knock out an article. So write articles? Considered it, but whenever I've tried to write for SEO purposes, keyword rich on something I have little interest in, it's like my brain freezes and it can takes
hours to write a few hundred words. Maybe the OP is also like that - has ability to do stuff but not fast/good enough to earn at it? It's a mystery to me why this is so but it appears to be.
I've got high hopes for the IBP site analysis at the moment but it'll have to be an email contact for first approach as I'm too inarticulate on the phone for an initial approach. But I'll try.
I've no doubt a lot of it is lack of self esteem and fear of failure, but there are so many of us out there. I have a very rich brother who has always considered me a flake and a loser - maybe these things affect one subconsciously and we self sabotage in some way? Some of us will quit, some won't, some will be forced to quit. How we get like this, and how we get out of that 'mind set', ah that's the question.
Haha I've got a little 'mind movie' running on the comp telling me I'm making loads of sales and I'll do it by doing x y and z, which I'm doing. I'm applying 'action' and I do believe in the law of attraction bollocks even though I've seen no sign of it yet.
I'll keep the faith but I can completely understand those who get defeated. (BTW I've had 2 sales of those products in 6 months - the first on Christmas Day which I considered a good omen for many more (and the customer loved it - the WeightLoss one). 'Twas not to be, hence I've stuck them on Amazon.