In my experience, cock size is one of the least important aspects of your perceived “market value” as a relationship partner.
But cock size can be a subjective “perceptual” factor on our behalf as men.
It will be hard for anyone but yourself to convince you that your cock is “just fine” as is… which is the basic concept behind penis dysmorphia.
Pumping will add girth but it’s a little like Cinderella in which each pumping session wears off and your body will want to come back to homeostasis… experienced pumpers make up for this with frequent sessions and or escalating size goals. There will be some semi permanent growth but it’s like lifting weights… you cannot lift for a year, then stop for a few months and expect for your strength to stay at the level it was before you stopped lifting weights.