Your description is a bit vague. You said you charged it yourself, but did you have the proper equipment to do so or did you just slap on the regrigerant to the charging hose and fill up?
If it works and then cuts out, this probably is due to one of the following:
1) The system is low on refrigerant
2) The system is overfilled
3) There is moisture in the system
4) There is a problem with the A/C Clutch Cycling Switch
5) There is a problem with the CCRM
6) Airflow to the condensor is restricted