It must be very hard to deal with her.
Looks like she is undergoing loads of stress. Suicidal thoughts and aggressive behavior points towards severe illness, probably depression.
Next Steps
I recommend to see a psychiatrist immediately to prevent any possible suicide attempt. in severe cases hospitalization may be required for short duration.
Health Tips
until seen by a psychiatrist, please do not leave her alone and someone must keep an watch on her 24x7.