Phone Line + Computer + Father-in-law = Games?

[First]

Ok before me and my husband got married he always played games on his computer. We live with his parents. His dad would always nag and complain when my husband played his games because he didnt have a job at the time. he had applications everywhere in town but nobody was hiring at the time, so it really wasnt his fault about the job. well he just got a job about at month ago and ever since he has been working, he has quit all his games and put everything into his job. well I have been having to reschedule my appointments to doctors and everything for about 3 weeks now because my husband's schedule keeps getting changed around and messing up my shcedule. My husband is my only way to my appointments. but everytime I try to use the phone to reschedule my appointments or make important phone call like to the bank, pharmacy, etc, my husbands dad is always on the computer. he has a facebook account and he gets on there and plays mafia wars all day long. the only break he takes is to get ready for work. he works nights so by the time he gets ready for work and leave the house, every place i need to call is closed. i have asked him if i could use the phone before but everytime i do, he gets mad and starts screaming and cussing. me and my husband have a seperate phone line in our room for the computer. his dad unplugs the main phone line and plugs it into his computer. ive thought about getting a phone so when i need to make calls i can plug it up into the phone line in me and my husbands room, but i tried it and it doesnt work right. Is there any suggestions on what i can do to keep all the screaming and everything down to a mininmum when I ask for the phone? or anything about any of this that may help me out. ive tried talking to him and letting him know the night before when I need to make calls but he always seems to "forget" everything i tell him. and also how can somebody sit there and call somebody immature and all kinds of names about playing games when the person complaining about all of it, does it worst than the person they are complaining about. i mean my father in law gets up about 6 or 7 in the morning just to play games. when he gets home around 1-2 in the morning the first thing he does it unplug the phone so i can get on the computer and play his games. i mean seriously.....games are ok as long as you dont dedicate yourself to them. i just need some advice because i have a list of places to call today, and it is some very important places. i needed to call them yesterday but everything was closed.