Asalaamu Alaikum,
Thanks for sharing your feelings and perspectives with us. I know its not easy for you to do so as our faiths are certainly a very sensitive issue for many of us.
I also grew up in a household that wasn't very religious. At the time my parents were quite new to the country and there were not many Muslims where I lived and we went to state Schools that were predominantly non Muslim. So I also grew up not knowing whether the religion of my parents was true or not. So in High School I started to embark upon a journey of discovery. I looked into all the major religions, as well as the perspectives of the disbelievers of God.
I started reading into the meanings of the Qur'an rather than just blindly reading the Arabic without knowing what the Qur'an is saying. I also looked into the Sunnah and the basics of the science of Hadith, the story of the life of the Prophet Muhammad (Pbuh) and the stories of all the Prophets. That is when my eyes started opening. It is only by gaining knowledge that our eyes will begin to open and we will gain clarity as to what we are in doubt of. The only religion that truly made sense to me was Islam. It is fully consistent without having any discrepancies in it like the other religions I looked into. I also discovered that Islam is not just a religion but a complete system of life, which covers every aspect of the life cycle of a human. The more I read and gained knowledge of Islam, the more I gained clarity and a firm belief that Islam was the only one true path to success in this life and the next.
What also helped me immensely was to connect to the Masjid which enabled me to feel as part of the Muslim community and to build a support network of Muslim's to keep as company. This is most important.
Know that the main reasons we begin to have doubts is firstly due to a lack of knowledge and understanding of Islam and the wisdoms behind why we are obligated to do certain things. It can also stem from bad experiences of religion from childhood and growing up. These doubts/feelings can gradually turn into resentment which can then turn into hatred, rebelliousness, pride and arrogance in the heart. Surely for those who have had bad experiences in childhood and whilst growing up, must get the relevant therapy/counselling to resolve their deep rooted issues. Otherwise they will turn into irrational hatred of an entire religion and faith. It is similar to hatred based on race and ethnicity.
This arrogance continues to develop in such people's hearts which then leads them to starting thinking that they know better and are better than following an organised religion or believing in a higher power. They end up thinking that they don't need religion or God to succeed in life. When that happens then the light of guidance is taken away from one's heart. Allah says:
"All those on earth who have behaved arrogantly for no reason, I will turn away from My signs. Even if they see every sign, they will not believe in them. And if they see the path of righteousness they will not take it. Whereas, if they see a path of error, they will take it because they have rejected Our messages and have paid no attention to them. (Qur'an 7:146)
Throughout the Qur'an Allah talks about those with a disease in their hearts and those whose hearts have made them become deaf, dumb and blind towards the truth. When looking into this further I established that this is due to such people who became arrogant against God. This arrogance then turns into having a rebellious attitude and this is what you will find in many of those who have hatred and enmity against Islam, as well as religion in general.
So I would suggest that you look into the Qur'an with its meanings with an open heart. Also reading into the life of the Prophet is life changing, reading about his journey from before Prophethood all the way until his death. Also read about the life of the Prophets. It is highly important that you approach knowledgeable sisters and/or try to join a local Muslim Sisters Islamic circle. Remember "we will become whom we keep as company". Also join any Islamic courses available to you. Learn, learn and learn. However be careful of the tricks of shaythan who will try to lure you towards learning and getting the perspectives from the wrong sources, from those who hate Islam and try their best to defame it and give the wrong perspectives on it.
Also carry on listening to Mufti Menk as everything he says is from the perspective of Islam even though he may not directly quote it sometimes. Also refer to Nouman Ali Khan as he specialises in giving perspectives of the Qur'an in relatiomn to every aspect of our lives. Also his style is unique and easy to understand in a modern context.
Also every night ask of Allah. Open your heart and raise your hands unto him and ask him for guidance and to direct your heart towards the right direction. Surely he wants to guide you but your heart has to want to receive guidance in the first place. We must be aware that our time here is very short. Surely we are not here without purpose.
The following are some free eBooks and resources that I personally recommend:
Biography of the Prophet Muhammad by Martin Lingshttps://islamicbulletin.org/en/ebooks/prophet/muhammad_martin_Lings.pdfSeerah - Biography of the Prophet Muhammad by Yasir Qadhi on Youtube:https://www.youtube.com/playlist?list=PLC89682017B43845DTranslations of the Qur'an with brief summarised commentary - Good for beginners:https://muftitaqiusmani.com/en/Books/noble-quran/https://darpdfs.org/tafseer-as-sadi/In depth commentary of the Qur'an:https://www.islamicstudies.info/quran/maarif/maarif.phpAudio commentary on the Qur'an by Nouman Ali Khan:https://www.nakcollection.com/quran-tafsir.htmlFree E books and resources for those looking into Islam:https://www.islamicboard.com/new-muslims/134286887-useful-islamic-information-reverts.htmlhttps://islamicbulletin.org/?page_id=5742If you need anything else then please do not hesitate to ask.