Big Sweep gambling

Q: My question is about gambling. In my country, we have something called Big Sweep.

How to play:
1. Buy a ticket at $3 each.
2. Draws on every first Wednesday of each month at 6pm.

Results:
If your ticket number matches any of the 133 winning seven-digit numbers drawn, you win a prize of at least $1,000 and up to $2.3 million. If the last two digits of your ticket number match any of the nine winning two-digit numbers drawn, you win $6.

Is this considered gambling? Many of my Muslim friends are playing. 

Helping one's parents if they are in need

Q: If parents have the financial means and large amounts of savings, do the parents have the right to pressurise their children to provide free meals for them - and save their own money or give their own money to Pakistan.

We know that we have to be kind and should not say uff to our parents but do parents have a right to do this? Even with their daughters who are married? Please could you let us know.

Doubting if impurity fell onto the toilet seat

Q: I have a question regarding washing a place that is najis. I usually can see when this particular thing falls on the toilet seat but I know some water did flick off my hand when urine was on it. I washed the inner half of the seat, but was doubtful if it had gone onto the outer edge of the seat. I can usually see it if it falls on all parts of the seat, but because the seat didn't have anything on it I am still doubtful that it may have flicked onto the edge of the seat. My thigh also touched those places thats why I'm worried if it transferred onto me. I also saw something flick off my hand, but cleaned the floor because it felt like it hit the ground and not the seat. All of this is putting a lot of doubt in my mind? What should I do?

Negative thoughts

Q: I am trying to feel close to Allah by not committing sins like avoiding porn and not mastrubating and not listening to music but the thing which is disturbing me is Shaytan. Shaytan is putting anxiety in me by making me think that I became pious. I will die soon. My health anxiety is disturbing me and I keepthinking that I may suffer from a heart attack, cancer, etc.

I am trying and I know it's Shaytan but over time it becomes miserable for me to bear that negative thoughts are circulating in my whole body. Please make dua for me and suggest a short wazifa to get rid of the waswasas and other thoughts from Shaytan that are overpowering me.