Not surprising and kinda expected. Russia has 4 times the population of Ukraine. That's huge man power advantage.
If Lysychansk really has fallen, it's the beginning of the end for Ukraine. It was the last major city in the region. After Lysychansk there are no more big cities for Ukraine's troops to hide in, no more big groups of civilians to use as human shields. Its all small towns and open countryside all the way to Kiev. If its fallen, things are going MUCH worse for Ukraine than we're being told.