If you often have doubts about the deen and the state of your iman, you should make sure you have studied and learned well the basic tenets of faith (i.e., aqida). Without that solid foundation, it is not surprising how a person is easily blown about with the softest breeze. Tie yourself down firmly with knowledge of your Maker, who He is, what His attributes are, what His relationship is with the Creation. Learn about the angels, the books, the messengers, the Last Day and the akhira, as well as the Qadar of Allah. These are the fundamentals that constitute the pillars of the Islamic worldview. Everything else in Islam is supported by these pillars, everything else logically is connected to these 6 pillars of iman.
Once you strengthen and establish these pillars, they will support you when you have questions because you can always go back and find intellectual and spiritual comfort in the foundations of your faith.
Recall the time, after the Prophet’s (s) Night Journey and Ascension (al-isra wal-mi`raj), when the mushrikeen came to Abu Bakr (r) and told him that the Prophet (s) claimed to have, in just a part of the night, traveled all the way to Jerusalem and back. Isn’t that crazy and unbelievable? they asked Abu Bakr, trying to shake his faith. But how did Abu Bakr respond? He told them, if that is what the Prophet (s) said, then it is true! And furthermore, if he already believes that the Prophet (s) gets revelation from the Heavens, then it is not hard to also believe that he could miraculously travel across the world in a short amount of time.
Look at the wisdom in this. If you already believe in Allah, in the angels, in miraculous books of revelation sent down from God Almighty Himself, in the messengers and their many miracles, including bringing the dead back to life and splitting the Red Sea, in the Last Day, when the the entire universe as we know it and beyond will be annihilated, in Heaven and Hell, in Qadar, the omnipotence of God and His dominion and control over all that exists…If you already believe in all these things with knowledge, then how could something like, say, homosexuality being prohibited shake your faith? Or the fact that men are supposed to lead prayer and not women? That is just intellectually inconsistent. If you can reconcile your reality with the existence of the Creator, the angels, and so on, how are you not able to reconcile your reality with, say, the moral permissibility of polygyny? At the very least, could you pause and admit to yourself that maybe there is something you are not aware of or that you don’t understand? Why would that doubt about such a relatively small thing destroy your belief in everything else? …Unless your belief wasn’t based on anything solid in the first place.