I don’t have OCD. I do have anxiety since I was a teenager. When my parents were alive they were repeatedly hospitalized so I know the feeling.
First, if this stuff is seriously interfering with your ability to function, seek help from a mental health professional.
Second, understand that having a parent in the hospital is a stressful event, and that even if you didn’t suffer from these conditions you would likely be feeling great stress/ upset at this time. Look into whether the hospital provides any resources, such as counselors or groups, for the family members of seriously ill patients.
Third, try to make sure you are getting adequate and healthy food and sufficient water (as in plain water, not coffee/ tea/ cola/ juice or other drinks with an additive) every day. Avoid alcohol. Sugar and caffeine can drive anxiety up in some people.
Fourth, try to make sure you are getting enough sleep. I know this is difficult for some people who get insomnia when stressed, but lack of sleep can really worsen anxiety.
Fifth, try sitting in Adoration as Irishmom said. Some people also benefit from meditative prayer of their choice, such as meditating on Scripture, or on the Rosary.
And remind yourself to trust in Jesus and that this too shall pass, as St. Teresa of Avila (<===anxiety sufferer) said in her “Nada te turbe” prayer.