Create separate SSH key for your personal account and your company. Named them with different extensions in your .ssh folder. Upload them to your github account and finally create a config file for your SSH
Create a config file in ~/.ssh/

vim config:

# PERSONAL ACCOUNT Github
Host github.com-COOL
    HostName github.com
    User git
    IdentityFile ~/.ssh/id_rsa_COOL

# COMPANY GitHub
Host github.com-COMPANY
    HostName github.com
    User git
    IdentityFile ~/.ssh/id_rsa_COMPANY

Setting up different config settings for each project:

CD to a project folder:

git config user.name "Your Name Here"
git config user.email your@email.com

Whereas you can have global Git Config:

git config --global user.name "Your Name Here"
git config --global user.email your@email.com


Example:
git clone git@github.com-COMPANY:COMPANY/

git cline git@github.com-COOL:USERNAME