Hello and welcome to e health forum.
It is unlikely that your signs and symptoms will be due to HIV or Hepatitis C, in the presence of normal serology tests for the same conditions.
HIV DNA PCR test - has zero false negative rate, and hence if a test is done after 2 weeks of exposure and the test is negative, it is definitely confirmatory of a HIV negative status. Hence since your test was done after 10 months, it is highly unlikely to be false.
There is no form of cross reactivity between HIV and Hep C viruses, and antibody response to each agent is completely independent of each other.
The best thing to do is to consult a infectious disease specialist who can examine you and decide on the proper testing modalities and treatment.