I agree with Azunaki. Don't give up, make yourself better. Do a few tutorials to improve on what you lack. But, personally, I think you should practice with common household items instead of organics. Modeling nearly anything can make you better. Make things like pop cans, flashlights, cigarette lighters, picture frames, small collectible figurines, speakers, computer chairs, keyboards and desktop computers, knives, tissue boxes, crayon boxes, cardboard boxes, furniture in general, remote controls, video game consoles, TVs, lamps, telephones, and the list goes on! Every single one of those items can make you better at texturing and proportional modeling.
Modeling organics can also accomplish this, but to make them look just right takes a nice amount of skill.
Take mine and Azunaki's advice, and you won't be sorry.