By denouncing a violent response to violent suppression of dissent by police, and maintaining that a violent response to violent suppression of dissent by police is wrong, you are endorsing and supporting police brutality against demonstrators, and setting it up as right and proper action. You may not like this being pointed out, but that is no one's problem but your own: it is what you have done.
You have not even attempted engaging the near universal consensus that people have a right to defend themselves against violence done to their person, and do so in such a manner as will ensure the attack ends. Nor have you engaged that it is only a moral position against all violence, by anyone, which is ever resorted to in claiming use of violence to defend oneself against violent attack is never justified or moral. It is evidently not a standard you could meet, from your commentary on the topic. It is clear yours is, really, a garden variety 'I approve of violence against my enemies and disapprove of violence against my friends' standard.
Part of the muddle which tends to arise when people think of violence and whether it is right or not is a confusion between decisions made on the basis of moral values and decisions made as considerations of strategy or tactics. As people must often be reminded, the fact that one has the right to do something does not mean it is the right thing to do in some particular circumstance, judged by considerations of what might succeed or fail, and what the gains or pains might turn out to be. Judgement of this sort might well conclude it is a bad idea to fight back in some situations, but that does not change that people have the right to fight back, or establish that in all situations it is a bad idea to fight back.
When engaged in conflict towards some political end, one reason often given some weight in deciding whether use of violence is a good course or not is whether use of violence will forfeit the proverbial 'moral high ground', and indeed, it can be of use in seeking some end against opposition to give the appearance of being better people than one's opponents. It is a pretty question whether behavior which aligns with a high moral standard, but is performed not from a desire to behave morally but rather from the calculation that it may pay to appear moral, should be considered moral behavior, or something else. It is something definitely worth bearing in mind, however, when considering this subject.
Non-violence, as a strategy, depends for its success not on minimizing violence but rather on seeing to it violence flows in only one direction in the confrontation. Violence remains at its heart, for violence is the ultimate test of sincerity in political matters, and a willingness to see violence done, whether by oneself or upon oneself, is essential to achieving anything. A non-violent protest met with slices of cake and soft drinks rather than tear-gas and clubs or worse, would achieve nothing. Again, it is a pretty question, particularly for people who adopt non-violence from a sincere belief violence is in and of itself wrong, just what are the moral culpabilities when one deliberately courts and provokes violence in others, and indeed depends up the violence of others for success.
Since maintaining a monopoly on use of violence for political ends within its boundaries is one of the distinguishing characteristics of whether a functioning state exists, the question of violence will always arise when people in any number challenge the government of a state. The state will certainly be tempted to demonstrate its monopoly, and of course it is likely to have more resources in that line. But a successful use of violence against agents of the state is, by token of that claimed monopoly, one particularly striking way the legitimacy of the state itself can be called into question. In any confrontation which aims, or comes to aim, at overthrow of a government, there will come a point when violence by the opponents of the state becomes an important means for them to stake their claim it is they, not the government they oppose, which is the legitimate power in that state.