Do you have industry buildings that close because they don't have enough workers? Or is the advisor nagging you, saying you need more workers? If it's the advisor, just ignore it. Those advisors can be relentless in their need to throw your city into turmoil. Remember, you're the mayor - it's your city and you don't have to do a darn thing they say.
First, check the population tab and look at the population details per wealth class. Check the demand for each wealth class vs. the population of workers. You're good if you can keep the unfilled jobs per wealth at half or less than the available jobs. You have 6,000 unfilled low wealth jobs, that's ok if you have 12,000 or more total low wealth jobs. If you have all your low wealth residential workers in low or medium density, upgrade the roads to get high density residential buildings and pack in some more workers. Sometimes, a small medium wealth district will help make the factories happy.
If you have plenty of workers for the jobs, but your factories are closed because they need more workers, the problem is usually traffic. Watch the road screens closely at shift changes; do you have traffic jams all over the city? If the worker Sims can't reach a job in about two hours, they just wander around and then find a house to go back to and complain.
Building the megatowers can help, but be sure you're placing it somewhere with a clear path to get to the industrial section. You want to be sure that all three entrances are connected to roads - otherwise all those workers will be streaming in and out of the building at the same place and same times, creating huge traffic jams.
Try not to have 4 way intersections; 3 way intersections are the best - and building commercial interspersed in your residential areas will help a lot because the sims will walk to work and shopping, freeing the roads. Aim for about 1 commercial building for every 3 residential buildings on the same road, then tweak as necessary.
And remember that changes need some time before you will see the effects. If you make a change to a road, watch it for a full Sim-day, to see if it helps make a difference in your traffic flow.
P.S. Your English is not bad, much better than I do in any other language 