Corrections in red.  Stylistics in blue.

I want to visit to the mountains!

Today I'm a little sad because I have to go to the dentist:), and the weather is awful - rain and wind...I feel lonely and want to talk with someone)).  My cat is a help to me.  )))) And I really want to go to the mountains!!!:)) I think I'll go soon.))

I want to see the mountains with closer look!

Today I'm a bit sad, because I have to go to see a dentist:) and weather is painful.

Rain, wind...ext.

I feel lonely and want to talk to someone to chat.

I really want to go on top of the mountains!!!

I am sure I will go soon:)