I wonder what causes you to lie, when you have information available that indicates the contrary.
https://en.wikipedia.org/wiki/2025%E2%80%932026_Iranian_protests
Are you perhaps related to some group which Israel has attacked? Then I would understand the desperate need to support any tyrant, as long as they are against Israel.
If I were you, I would critically examine my news sources.
You are misinformed.
Do you actually know that war in Eastern Ukraine started in 2014? Have you read the timeline?
Yes, when a land war occurs, both sides will be shelling each other.
The casualty numbers due to Ukrainian fire (you forgot to provide casualty numbers through Russian fire - why did you forget? were they too big?) are unlikely, though, since it was a low-intensity conflict. But it was intense enough to drive 1.6 million people from their homes over time.
At some point, a ceasefire was reached, with sides agreeing to remove heavy guns and missile launchers to a distance from the line of contact. Then the ceasefire failed. At all points, Russia was supporting an army of approximately 30 000 to 40 000 soliders in Eastern Ukraine, and equipping them with everything from small arms to heavy artillery.
You mention "Putin's justification for invasion". He was already invading Ukraine in 2022. He had taken Crimea in 2014 and had been trying to take Donbas ever since, with low intensity warfare.
His true grievance was that Ukrainians had a revolution in 2014, and drove out president Viktor Yanukovich, whom Putin had friendly ties with. He responded with military force.
Please, study history. Do not let propagandists twist you around a finger. History is complicated but if you want to be adequate at politics, you must understand the topics you speak about.
https://en.wikipedia.org/wiki/War_in_Donbas