GSM and GPS module don't work together
You can't use two softwareserial devices together (or not reliably, and not without knowing exactly what you are doing).

It's not even easy using one software and one hardware serial together unless you know what you are doing.

SoftwareSerial blocks everything else from happening while it's sending or receiving, so using it for things that send unsolicited messages (as GPSs do all the time) causes havoc.

The best you can hope for is to use HardwareSerial for the GPS and SoftwareSerial for the GSM, which is call-and-response most of the time.

Better would be to use a better board that has multiple hardware serial ports.