Greetings !
Keeping all your history in consideration the best and safe medication as augmenting agent are
1) lamotrigine , but it needs slow and gradual titration and may show results after some weeks.
2) And the other option among antipsychotic medication is small doses of aripiprazole which is very weight neutral and will not cause impairment in blood
sugar.
These options are very safe condsidering your prediabetic state and hypertension.
But its better you consult a psychiatrist online or in person , so that he can prescribe you these medicines as they need to be taken under strict supervision of doctor.
Next Steps
consult psychiatrist
Health Tips
Please Do not try to self medicate your self. Take professional help.