Hey there! I´ve been trying to create my own characters and stuff, but every time I try, they really suck in the end and I don´t know how to change it. Especially when I draw from memory, so at times I get really frustrated and don´t know what to to anymore. I want to engage in this field of work. Character Design is so awesome but somehow I start doubting that I´m able to do it, maybe I´m too stupid to get it right. Do you have any advice for me? How do you start doing a character?

Ohmy. I know this kind of frustration. I sadly don’t know any of your work to give specific feedback since you are an anon, but a general advice is to start thinking about your character BEFORE you start drawing. Not only about character traits (what a character likes and dislikes etc) but also about the feeling you want to evoke in the people who see your character design. Like “I want people to feel disgusted by the character, but still a little bit cute” Don’t just jump into the visual design progress without a plan… It doesn’t have to be a long and perfect description. Even just catchwords can do the trick.

Then I think about the visual things…Like forms and color (I’m a drawing type so I go with forms before color, but that’s different for every artist I guess) This is the point where I look around for references and inspiration, because i don’t want to copy an existing design. I want the general “feel” of the character in my head before I start looking around!!
And I always try to draw many many sketches before finalizing a design. Just do it like you would do a brainstorm. Try many different things, even if they don’t seem to work at first - also combine sketches and just go wild. 

There are many good tutorials around on the web for this stuff. Like these:

And for references i specially like this board:

Hope it helps and good luck!