Your "symptoms" sound like anxiety. You don't have hiv, as stated above, and you don't need further testing.
You don't have HIV you have a conclusive test result.
HIV testing after 3 months is 100% conclusive
You can absolutely trust your 4-month conclusive test result. There is no need for further testing.
As for the rashes, they could be cause by a number of different things/illnesses - an allergy (examples: food, laundry detergent/sheets, soap, lotion, perfume), stress/anxiety.. The best any of us can advise at this point is to seek medical attention for strictly rash and not HIV. :)