New Muslim feeling like a failure

Q: I am a new revert and my family doesn't know. They would completely disown me or hurt me if they knew. I sometimes struggle with doing prayer because they are there and lately I am also taking care of my sick father and cannot always do wudu or find the qibla at the hospital for prayer. What do I do? I feel like I'm failing.

Calculating zakaat according to the nisaab of gold and silver

Q: If in 2017 and 2018 a person followed the silver nisab but happened to not pay Zakah in those years despite meeting the silver Nisaab then at a later point (maybe 2018 onwards) he moved to the gold nisaab and when he did calculation for past Zakah, he used the gold nisaab retroactively, even for those years where he followed silver nisaab but that meant for those years he did not owe Zakah according to gold nisaab. Would he be required to still pay Zakah for those two years because at the time of those two years he was following silver nisaab?

Questioning Allah Ta'ala

Q: If this worldly life is a test for the eternal neverending hereafter life in hell or heaven then why to bring a new innocent infant into this test of worldly life and afterlife test of heaven or hell after knowing that the probability of going to hell is extremely high? What is the reason of bringing children into life without selfish reasons? Even it is not compulsory?