Sex is SO BAD after marriage

Well my hubby and I are married for half a year now. We've been very active before and had so much sex but when we came back from our honeymoon sex was just so bad
Idk what happened we dont have any problems we're very happy with each other we dont have money or health issues or anything. Not stressed because of work we both work in an office just basic not too much.
I did tell him about how I feel and he thinks the same way but we just dont know why and whats wrong. Advice? 
And is it always like this after getting married?