Will God punish a girl with not getting married for removing her niqab after wearing it for two months, especially since she studies Sharia and fears that this might be a punishment from God?

Covering the face is a matter of scholarly disagreement, with the preponderant view being its obligation. Sins have an effect on the one who commits them, and what has befallen you may be a punishment for removing the niqab. Wearing the niqab is more pious in the sight of Allah and absolves one of responsibility. It may also bring you good and facilitate marriage, for it is not true that wearing it prevents marriage; rather, men may desire it because of the niqab. Do not despair of supplicating Allah in all your affairs.