Stay with SSDI or take "Reduced" Widow Benefit?

I am a 47 year old disabled widow with no children. My SSDI benefits were calculated from my own personal earnings. It has been explained that I am eligible for survivors benefits when I turn 50 (instead of 60) due to being disabled, but it will be 75% of my husband's benefit unless I wait until age 67. If I were not disabled, the 75% survivor's benefit would begin at age 60 and gradually increase every year until the full retirement age of 67 for a healthy person, but this 7 year transition does not apply to a disabled person. I could survive "barely" if I were to receive my husbands benefit at the 100% but at 75% it is not much more than my current SSDI and will never increase past the 75% for the rest of my life - currently my Mom helps me but she was diagnosed with pancreatic cancer, and the future looks to be perhaps very frightening... especially when I'm in my late sixties and everybody in my family is gone. Any thoughts? I know they have a bill presented during every new congress to change this, but it never seems to get anywhere. I read that the impact on Social Security to make this change would be less than .0001%