i was told from ssdi not enough credits

hi all,
please help, I am very depressed and not sure what to do about ssdi.
I did apply feb 2010 and received a quick response and was told I didn't have enough credits to receive ssdi, even tho I worked a lot full time, I was off due to spine issues and when they went back that was time I was off work due to having a child.
So they did state in letter they are not denying me at this time but would send on to ssi. And I haven't heard anything.
So I asked few people they said just wait, but I'm wondering if I need to fill out the ssi forms.
I tried to work from home doing some Avon for last year but just can't do that due to I am now on oxygen and hard for me to get in and out of my car with all my spine issues also.
So does my home business count as working hours??
Please help I know with all my disabilities I should be getting something I work since I was 15 yrs old and although yes there were few years I didn't work that shouldn't be fair to deny me.
So I guess my questions are should I just apply all over for ssdi and say I'm still working even tho I am not making any money at all from Avon. Or should I just apply for ssi??
Any suggestions would be of such help.

thanks
mary