I'm not saying that you should leave your current job, I would never tell someone to leave their job.
You need to decide what is best for your future, how much money you can earn?, where you want to work?, will people want your skills?, will you have to move?
I can't tell you which job to do because your situation is different from mine.
I gave you my experience, I could pursue another career in 3D Art/CG, but I personally prefer the challenge that web gives me.
You have to decide what you want from your job, it's completely your decision and based on your situation.
There are lots of questions to ask yourself, things like:
Do I enjoy what I do?
Is my pay high enough?
What is my future in this job?
Can I progress further?
These questions can only be answered by you, I don't know how much money you need to earn, or if you can keep working in SEO in the future.
Your priorities are probably different from mine, personally I want to be happy with my job and I have people that can support me if I need it, but this may be different for you.
I won't tell you what job you have to do or what you should do, but you need to think about what you want and where it will take you.
I hope that helps.