Fear of performing salaah with jamaat in a musjid

Q: I have researched about it deeply and I can conclude that there are cases in which it is recommended by our religion to pray alone instead of attending congregational prayers such as when you feel that your life or assets are in danger, in state of fear of your death, etc. Hence my situation is that I love to pray in the masjid with all the people together but whenever I enter the masjid, I suspect everyone as a suicide bomber. During whole prayer I am not able to concentrate in my Salah, this happened more intense when I bring my kids with me at Juma or even daily prayers. During prayer I start to imagine blood and body parts on the carpet and during whole prayers my mind is busy in thinking that if it really happens, how I will save my kids? From where will we escape, etc. I feel much better praying alone in my house or more better in an empty masjid. My question is that in that case what should be the right thing to do?

Born circumcised

Q: My age is 27 years and I am not married. When I was born I was not circumcised. Recently when I went to the doctor for circumcision, the doctor told me that I do not need circumcision as there is no foreskin over the head of my private part. In medical terms this condition is called aposthia, which is rare, in this case there is no foreskin naturally to be removed. When my private part is flaccid, the skin doesn't cover my private part head and also doesn't cover when its erect. But there is very little foreskin which, when I pull then when my private part is flaccid it retracts back. My private part looks like it is naturally circumcised but in actual fact its not. I am curious to know whether I still need a surgery to remove more skin or its just fine and I do not need to undergo a surgery. Will I commit a sin if I do not undergo circumcision? What does Islam say about natural circumcision?