I am technically a manual tester and I just changed companies and literally had a slew of companies trying to recruit me. Q&A work in general is exploding as companies see how much value it offers them as a whole.
I have a feeling your issue falls into 2 categories.
A weak resume (Easily fixed)
Lots of experience with little to show for it
The question you have to ask yourself is how do you remedy this. A weak resume essentially means you are being screened out by the software screeners. Include the keywords for the position you want (use google adwords to find the keywords that recruiters are searching for, include it in your resume).
Also another good trick is to include your accomplishments. Saying "I am experienced with Test Planning" is one thing, saying "For the previous 3 years I have been organizing, developing, supervising and executing testing operations", which is likely closer to what you are doing, is better. And then provide examples of that experience.
As for accomplishments, you have to communicate what makes you a stellar employee and, probably more importantly, why are you still 'just a manual tester'. I was asked this several times since I have extensive experience in nearly all aspects of the SDLC. The easiest answer, I am passionate about testing and love my job.
I hope this helps you out. Manual testing is still extremely important and needs more quality people in the field. A lot of people use manual testing as a stepping stone without realizing that the best manual testers can earn well over 100k while still enjoying their job.