Is it possible to give yourself an std from saliva lubrication during masturbation?

Doubtful: That could only occur if you already had an infection in your oral cavity due to one of the many organisms that can be sexually transmitted, and even then, saliva is inhibitory to many microorganisms. You should be fine.

Yes: If you have oral herpes simplex virus i infection on your lips you can spread this to your genital area by saliva. If you have an active std in your pharynx such as gonorrhea this could then be spread to your genitals by saliva.