I am looking to symmetrically encrypt/decrypt information in a database. This info consists of short pieces of information, which need to be individually encrypted when a specific method is called.

I have been researching using AES_256 in GCM mode, but keep coming across the recommendation that I should not "roll my own cryptography protocol". 
see these links for examples

https://security.stackexchange.com/questions/2202/lessons-learned-and-misconceptions-regarding-encryption-and-cryptology 

https://stackoverflow.com/questions/4453724/aes-encryption-of-files-with-python

I need to actually *incorporate* the encrypting/decrypting in code. 

Can I viably use GPG or PGP to encrypt/decrypt code, and if so how?

If not, any suggestions as to the best library to use for AES in GCM would be appreciated.

Thanks