How do I apply for Social security disability

If you have paid into the Social Security system, you may qualify for Social Security Disability Insurance (SSDI) in an amount equivalent to your Social Security retirement benefits and, once you have received it for 24 months, Medicare.   If you have not, or if your SSDI does not equal the Supplemental Security Income (SSI) amount ($771 in 2019) and you are not able to engage in "substantial gainful employment" (earning at least $1,229/month in 2019), you may also qualify for that.  In Texas, one dollar of SSI qualifies your for Medicaid.   It is not clear which you applied for or what you mean by "regular" and "disability" benefits.   In general, the key to obtaining Social Security benefits is to thoroughly document your condition, respond promptly, and repeatedly appeal.