Essalamou alikoum,
I think my brother that your source of doubt is coming from a lack of information or non truthful side of Islam and yourself as a human, excuse me for saying that you should read a bit about universe and science more deeply, not just what atheist try to show to people, I am a physicist and I am muslim not because my father was a muslim, but because I believe and I am certain that islam is true. From the point of science, you should not just follow without proof, even yourself. Ourselves have some fantasmic imaginations that we should polish them with our minds. From the point of Islam, the Islam is asking his followers to be reasonable and use scientific approach in their lives, in many chapters in quran God says
''And We have made the night and the day two Signs, and the Sign of night We have made dark, and the Sign of day We have made sightgiving, that you may seek bounty from your Lord, and that you may know the computation of years and the science of reckoning. And everything We have explained with a detailed explanation. ''
'' We created man from an extract of clay. Then We made him as a drop in a place of settlement, firmly fixed. Then We made the drop into an alaqah (leech, suspended thing, and blood clot), then We made the alaqah into a mudghah (chewed substance)...''
take these verses of quran and compare them to what the actual science discovered and judge by yourself. Quran is encouraging people to find a wrong information in it, but no way, it is the unique book on earth that starts with ''this book contains no doubt'' . It can be a long discussion, but just focus on being scientific and check facts yourself and do not listen to others to guide your future and In shaa Allah all your doubt will disappear. Salam