I cant stop to worrying if I don't wash my hands ,is it OCD?

[Shana Av]

I had my fears since I was child,but the worst was I was afraid to make ill other people if I didn't wash my hands properly or if my cloths were dirty so the people I loved might get ill ,I was better really but before New year days I started to clean the house alone (I am living with my sister ) my sister came home from outside making the floor dirty and dusty and I don't understand why but I got so angry telling her why she didn't take off her shoes but she didn't respond and even started to walk more on the floor i started to clean again and I was so tired that day ,from that day on I think that disturbing OCD is back again and even when I look to that floor i am feeling angery and the desire to wash my hands again and again ,please help.