Question 047: Is mourning for Imam Hussain (a.s) while you are grieving allowed?
Answer 047: There are no restrictions limiting the time of mourning for Imam Hussain (as) to the Day of Ashura. When you are grieving for any worldly things and want to forget about them you can remember the tragic incidents that took place in Karbala against Imam Hussain (as) and His family and Followers.
In this regards, Imam Reza (as) said: O Son of Shabib! If you want to cry over something, then do so over Husain bin Ali bin Abi Talib (as). This means that if you are grieving you would be recommended to mourn for Imam Hussain (as).[1]
Arabic version:
يَا ابْنَ شَبِيبٍ إِنْ كُنْتَ بَاكِياً لِشَيْءٍ فَابْكِ لِلْحُسَيْنِ بْنِ عَلِيِّ بْنِ أَبِي طَالِبٍ ع
Also, there is a hadith in which Imam Ali (as) said: If you cannot be patient, then act as if you are patient (i.e. behave like a patient person), because it is very unlikely that a man make himself like a group of people but does not become like one of them.[2] We can find a similar saying suggested by psychologists: Fake it till you make it.
Arabic version:
إِنْ لَمْ تَكُنْ حَلِيماً فَتَحَلَّمْ فَإِنَّهُ قَلَّ مَنْ تَشَبَّهَ بِقَوْمٍ إِلَّا أَوْشَكَ أَنْ يَكُونَ مِنْهُم
So, according to the previous mentioned ahadith, you can mourn and cry for Imam Hussain (as) anytime you want even when you are grieving.
For further information in this regards, please refer to the following answers:
Index: Cry or Pretend to Cry over our Sins, for Imam Hussain (as) or Fear of Allah (SWT), 048.
Index: Qama Zani / How the Infallible Imams (pbuth) mourned for Imam Hussain (as), answer 507.
[1] . Al-Amali of Sheikh Sadouq, al-Nass, Pg. 130; Uyūn akhbār al-Riḍā (as), Vol. 1, Pg. 299; Wasael al-Shia, Vol. 14, Pg. 502; Bihar al-Anwar, Vol. 44, Pg. 286.
[2] . Nahj al-Balaghah, H. 203.