Keep practising and put short notebook entries into italki. Listening to as much English as possible. from a diverse range of subjects. Try not to listen to pop songs, there are some pop songs and artists where the lyrics are in good standard English, but often they are written in cryptic language, and for English pop songs, it's generally all about the words matching the music, with unnatural phrases.

Avoid too many soap operas. Ask in the discussion section, for recommendations on what to watch and listen to from experienced English teachers. Not other learners because some are very likely to make some poor suggestions. 

Also remember that online internet "what's my level" tests do not give a true indication of your level. Many of them actually state this before you start. I would say you are at an intermediate level but not upper-intermediate. You are above beginner, but where exactly on the European CEFR I do not know. 

Songs:

I actually do not like the Beatles, but the lyrics in Beatles songs are always in standard English that uses everyday collocations. 

Abba the Swedish group the same applies.

Simon and Garfunkel, or Paul Simon as solo singer for standard collocations in the songs.

There are many others to choose from and you may not like my other suggestions you possibly may not like the ones I just gave.

Television.

The news programs, programs about current world situations, discussion programs and some older films, generally speaking the older films used standard good english either American, British or commonwealth. More Modern films use street language. 

put your suggestions and likes in a discussion and other Teachers will tell you if you have made a good choice. Good luck with your studies.

I did/have done some English tests for estimating my English level, I am in the upper-intermediate level! How much longer would it take me to reach an advanced level?.

It should be a few months to a year maximum, but your snippet of text is not near intermediate level, yet.

As I have done some English tests for estimating my English level, I am in the upper-intermediate level! How much longer would it take me to reach an advanced level?.

As I have (already/previously) done some English tests for estimating my English level, I am in the upper-intermediate level! How much longer would it take me to reach an advanced level?.