Feeling lost - my partner passed away from lung cancer late last year

My partner was diagnosed with lung cancer in October . we went away on a short break before his chemo started in December he got pneumonia and passed away on the 10th 
So many ups and downs, 

I don’t know what to do, people say so things when you ready . How do you know when you ready? It’s driving me crazy being in the house , alone. I’m thinking of going back to work, but then panic about it. 
 everyone thinks I’m coping but I don’t believe I am and don’t want to put more stress on family and friends by telling them!!