You may be entitled to occupational or company sick pay on top of Statutory Sick Pay − this should be explained in your employment contract. 

Your employer may run it's own sick pay scheme - often called an occupational or company sick pay scheme. 

If you are self employed you can still apply for benefits. Your entitlement to any benefit will depend on your personal circumstances, income, savings, care and/or mobility needs. 

Please contact a benefits adviser for advice. 

Macmillan have a booklet called Self-employment and cancer which you may find helpful.