I always dress with black and I want to change but I don't feel good wearing another colors what can I do

Two ideas:
One: Add black with other colors. Like if you have a black jacket or button up shirt wear another colored shirt underneath. If you wear it with jeans it will look like you're not trying to wear all black (unless the jacket is a trenchcoat, that still wouldn't look right) And if you want to wear a black shirt try wearing a pair of kaki's with it, this way it off sets the color.

Two: Sell all clothing at yard sale and go out and buy new clothing with no black. This would force you to wear other colors. (I think the first one's better, I hate selling clothing myself)

Black is a color (well... shade), not a lifestyle or emotion so try not to think of it as one.
Have fun with your clothing, black is a good color it can look great if you wear it right.

Start by purchasing a pair of brown, grey, and navy slacks(and/or skirts) to go with any black slacks you already have. Then, purchase a light pink top, a white top, and a light blue top.

Purchase a navy blazer and a black blazer if you don't have the black one

There you have the "bones" of the start of a wardrobe that is easy to mix and match. Have a nice leather belt and leather shoes.

Good Luck!

Pretty much like the others said, start by adding color to the clothes you already have.
Like add a deep colored (navy or purple or hunter green) jacket to a black dress or pants.

Add a bright multi colored scarf to any outfit.

Wear a white shirt with a black skirt or pants suit.

Try adding colorful jewelry as well.
As you get more comfortable wearing a colorful accessory or jacket keep adding another color.

I used to be the same just gradually introduce new colour push yourself out of the comfort zone. Just try not to be put off when someone says "OMG she's wearing colours!!!!"

I started by adding greys and then reds and purples because they look good with black. Sometimes I'll even wear pink now so you see they is hope for us all.

And if you try colur and just don't get on with it don't worry you can never wear too much black really... Just be yourself and do what you want ;)