What would you charge for this type of house-sitting request?

Trying to figure out what I should charge for house sitting, etc.

This is a regular client. He's booked with me in the past. The thing is, he's gotten rid of his dogs that I used to sit and now has a puppy. Generally I charge $45 for an overnight for a puppy. I'll generally do 1-2 drop-ins as a courtesy, upon request. The thing is, his puppy takes quite a bit of time and care. I mean, what puppy doesn't? This one, however, you cannot take your eye off of him. I'm talking, I have to take him to the bathroom with me to keep him out of trouble. Now, that being said, my client is requesting that I stay overnight, as well as provide 4 walks and 4 drop-ins for the $45 rate. I am no longer comfortable doing this. If I scheduled these separately it would come to a total of $173 for 1 overnight, 4 drop-ins, and 4 walks. Even giving him a 50% discount on that price it would bring the total to about $87.

I did this for $45 for him 2 other times, but since researching rates a bit more, and my overall stress with other bookings, I don't feel this is adequate payment for my time, gas, and services.

Can anyone give me some advice? How much should I charge? How do I go about advising him of the rate increase? What do you charge for house-sitting, walks, and drop-ins combined?

Thanks in advance!