All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and messenger.
First of all, we ask Allaah to reward you for your desire to do good and to stay in the mosque. We ask Allaah to increase you in piety, righteousness and guidance.
There is no doubt that there is much goodness and blessing in the mosque. In fact, if a person performs the prayer in congregation in the mosque, Allaah will multiply his reward. If the heart of the person is attached to the mosque, he will be among the seven people whom Allaah will shade under His shade on the day when there is no shade except His. Whoever goes to the mosque, Allaah will prepare a lodging for him in Paradise - whenever he goes whether in the morning or evening. And there are other Islamic texts which are reported on the value of going to the mosque.
Nonetheless, we do not know the reason why your mother dislikes your going to the mosque. So, you should try to find out the cause and work on eliminating it. It could be that your studies are among these reasons, in which case you should focus on your studies, and the mosque should actually be a reason to motivate you to achieve more success, and not to set you back in your achievements.
It might be that the reason is her fear and concern that you may be influenced by some extremist ideologies. If you know that this is the reason or you predominantly think that this is the reason, then you should comfort her by saying to her that you are adhering to moderation.
Some people may believe that being religiously committed is a cause of insanity due to the ideologies of some deviant Sufis and other deviated sects. At any rate, you should try to find out the reason and solve the problem accordingly.
If you fear that staying too long in the mosque away from home is what is causing your parents being strict with you and preventing you from going to the mosque, then you should adopt a balanced attitude; which means that when you finish your obligatory prayer in the mosque you should not stay there too long.
In summary, you should be wise in dealing with your family and try to be courteous with them - especially your mother - so that you avoid them being angry with you. For more information, please refer to Fatwa 89383 on being patient with the mother's offense and showing kindness to her in all cases.
You need to attract their hearts so that you can influence them to tread the right path. For more information, please refer to Fatwa 87573 which is about the importance of being merciful in inviting parents who are far from the spirit of commitment to religion. If they are really far away from being committed to religion, then there is no doubt that they will be only concerned about this worldly life and be neglectful about the Hereafter, but this should not undermine your determination and make you despair of continuing to act virtuously.
In conclusion, we emphasize that you must be kind and dutiful to your mother, even if she mistreats you. You should try to avoid making her angry as much as possible. You should also supplicate Allaah to guide her heart to what is good and bless her with guidance and uprightness. Supplicating for her is among the greatest means of being kind to her.
Allaah Knows best.