Feels like something on the very back of my tongue when i swallow, what could this be?

Uvula: The uvula is a bell-shaped organ that hangs from the roof of the throat. Sometimes infections, inflammation, allergic reactions, rare genetic conditions, or trauma to this and the surrounding tissues, can cause swelling. You should make an appointment with your physician, for a history and physical examination, to assess the cause of this and discuss treatments if necessary.

Globus phryngeus: Sometimes when a person's stress or a bit sad, the throat muscles contract. "There's a lump in my throat." The foreign body sensation is distressing though there is no foreign body. Maybe you have this.

Possibly reflux: In addition to simple muscle tightness, irritative sources, such as reflux (in the absence of heartburn symptoms) or allergic nasal drainage, sinusitis drainage, etc. can cause a sensation of something in your throat. If it persists despite reflux or allergy treatment, it is easy for an ENT to examine and diagnose the issue.