The short answer is no there is no problem with attending more than one church.
However there is another more important question and that is “Should I attend more than one church”? I say this because being a member of a church is an important thing - its important for your wellbeing as a Christian as well as others.
You see when you become a Christian, you become a member of God’s family which meets each week in various places all over the world. You go to church to hear from God’s word, to respond to it in prayer and song and to encourage other members who are there. As a church member you go in order to be encouraged as a Christian. But as a member of the family you go in order to encourage other members to be Christian. So you go not only to get something out of it but also to give to others.
Churches can be difficult places, after all they are full of sinful people like you and me. But hopefully they are also all trying to be godly as well. In your church it sounds like there is a fair bit of ungodliness happening and maybe you have been the target of some of it. One way to handle this is to move churches and sometimes this is quite appropriate. You have done nothing wrong by going to another church.
But sometimes the best way to handle this is to stay and try to show those who are sinning that they ARE sinning and help them to repent and change. This is harder to do but also may be much more worthwhile in the end. I cannot tell you what to do because I do not know the circumstances. However I would encourage you to think about staying and trying to work through the issue.
About going to more than one church - the question comes down to how many people can you help and encourage to be christian? For most people it is difficult to be involved in more than one so I would encourage you to choose one or the other. But if you choose to go to both, you are not doing wrong.