No one can be diagnosed with an eating disorder through one instance or one acute cluster of instances. Eating disorders are chronic patterns of behavior that have deep-seeded emotional and cognitive roots. Bulimia, contrary to popular belief, is not that one vomits after eating too much. Bulimia is repetitively purging what one eats (vomiting or otherwise) as a guilt response to bingeing...which is classified as the intentional consumption of extremely high amounts of food volume and calories in an uncontrolled fashion... like a drug addict seeking for their substance and not being able to help themselves.
Bulimics will eat up to 10,000 calories or more in a day, shoving whatever they can into their mouth knowing even before they keep eating it that they don't need or want it but can't help it.
Eating too much and feeling too full and then attempting to vomit is not an eating disorder in and of itself. The psychological reasons behind what you did and felt and how you chose to handle it, along with whether or not this type of behavior becomes repetitive for you, will determine whether you may have an eating disorder.
PLEASE, if I were you I would be so thankful to have begun identifying this problem before it turned into a full-fledged disease and take this opportunity of introspection and awareness as a motivator to go see a therapist and help yourself before things get too out of control that you can't.
Whether or not you would benefit from losing weight does not matter in a case like this, as even if you are overweight (and I don't know if you are or not), it is important to do so in ways which are healthy both physically and mentally, and I think a therapist could definitely help you with figuring out how you can define this for yourself as well as some of the reasons as to why your relationship with junk food is so upsetting to you emotionally.
I hope this helped!! Please ask for all the help you need, I am here for you!