I am not able to download or update any application.

i also changed my password after that.

See this Apple article: What to do after you change your Apple ID or password

What to do after you change your Apple ID or password - Apple Support

Actually someone misused my apple id

See the following Apple articles:

Recognize and avoid phishing messages, phony support calls, and other scams

Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support

If you think your Apple ID has been compromised

If you think your Apple ID has been compromised - Apple Support

Create a strong password for your Apple ID, It is best if your password consists of eight or more characters and include upper and lowercase letters, and at least one number. You can also add extra characters and punctuation marks to make your password even stronger. 

Never provide your password, security questions, verification codes, recovery key or any other account security details to anyone else. Apple will never ask you for this information.

I am not able to download or update any application.

See this Apple article:

If you can’t download or update apps on your iPhone or iPad

If you can’t download or update apps on your iPhone or iPad – Apple Support (UK)

You may need to have a payment method on file, even if the app you want to download is free. Check which payment method you have on file 

Sign in to your Apple ID account page and edit your Apple ID details.

https://appleid.apple.com

On the Sidebar click Payment methods -> then tap Payments Methods and tap Manage payment method.

See  also the following Apple articles:

Change, add or remove Apple ID payment methods

Change, add or remove Apple ID payment methods – Apple Support (UK)

Add money to your Apple ID balance

Add money to your Apple ID balance – Apple Support (UK)

Payment methods you can use with your Apple ID

Payment methods you can use with your Apple ID – Apple Support (UK)