You need to make a realistic plan for your business.
What is the demand for your product? Pretty low. It's not easy to make money as a painter.
You'll probably need to attract a
large number of visitors in order to make any decent income. You can only expect a small proportion of them to buy -- about 1% or less, not 10%. This also assumes that most of your traffic is coming from
relevant searches or links (i.e., at least vaguely interested in buying paintings).
Let's say, for sake of discussion, that 1% of visits result in a sale of £15. In order to make an income of £30,000 p.a., you would need to make 2,000 sales, which means 200,000 visitors (about 17,000 visitors per month).
So you need to increase your traffic by a factor of about 1000 to earn a full "wage", or a factor of about 100 for a nice sideline. Anything less, and it's a hobby.
These are just assumptions, of course; but since you don't have any real data yet, we have to make assumptions. Your
real business prospects could be much better or much worse than these estimates suggest.
But, based on these assumptions, you'll need more than some
SEO fiddling to make the business lucrative. A little optimisation here and there will not produce such a dramatic change in your traffic. The problem is much more fundamental than, "Have I coded this site right for
SEO?"
Do you know what search terms you are competing for? Have you considered an AdWords campaign? Do you have other means of marketing your work?
By the way, your paintings are great. I'd love to be able to do that.
