I am almost 49 years old and my husband died 2 years ago on April 10th 2014. I was told i could not draw his retirement benefits until I was 62. Is that correct even when both of my sons are disabled and one draws a SSI check now.
You must be at least age 60, or age 50 and disabled, in order to qualify for widow's benefits. However, you may be eligible for mother's benefits at any age if you have children in your care who qualify for child's benefits on the account of the deceased wage earner, and are either under age 16 or are disabled. So, if your sons live with you qualify for Social Security benefits on your husband's account, you may be eligible for benefits now. If both of your sons are over 16, however, you must establish that at least one of them is disabled and require your assistance (e.g. live with you and have a mental disability or need help with bathing, dressing, etc.).
You say that your disabled son is receiving SSI, which is normally used as an abbreviation for Supplemental Security Income. That is a needs based program administered by the Social Security Administration, but not funded by Social Security taxes. So, I can't tell from your question whether or not he's receiving benefits on your deceased husband's record. In order for children to qualify for child's social security benefits, they must be under age 18, under 19 and still in secondary school, or disabled prior to age 22. They must also be unmarried and meet the relationship requirements (e.g. natural child, dependent stepchild, etc.).
If you think you may meet the requirements described above, you should re-contact Social Security ASAP. Keep in mind, though, that Social Security has an earnings test that applies to mother's benefits, so if you are earning substantially more than $15,720, you may not be able to receive benefits even if you meet all of the requirements.