Finding purpose in life with a mind that questions everything

I question things all too much, which is a blessing and a curse. It allows me to see through things that others take at face value and not inquire more about. However, it leaves me struggling a lot to find purpose in life. I went through a period of investigating different religions to see which ones aligned with my own beliefs. All of them are beautiful in their own way and offer a humble and purposeful approach to life, however I struggled to really 'get into' any of them, if that makes sense.

Hinduism and Buddhism were highly intriguing since atheism is also mentioned (Buddhism more so, only a small number of Hindus are atheist). Although I'm open that I may be biased towards these due to many of my ancestors likely being Hindu or Buddhist.

The atheistic worldview makes the most sense for my brain ,scientific findings (age of Earth and universe etc) and the theory of evolution seem highly likely in my opinion.

However, I'm not narrow-minded, and I understand that transcendental beliefs can be extremely powerful for other people, and make them better as a whole. Many of the people I get on with are religious, and they know I'm an atheist. They open up to me about their worldview and principles, which is nice. 

I can also see how nihilism can come to easy to some atheists, myself included. In my opinion this can be an unhealthy way to live life.

Ultimately for me, the purpose of life is to find purpose and to try to make it a better place for others. Regardless of belief, human decency, respect for others and open-mindedness can be easily achieved. I think this is a philosophy in it's own right, it might be existentialism?