im so sorry that is terrible, i hope he gets better :].
Ive no idea what you must be going through - ive lost people who were thattt close to me, but its always been so sudden there was no time to dwell on it beforehand.
But i can tell you that that feeling of feeling guilty to be happy happened to me SO much. if i forgot for a split second what had happened at first i would just start crying, scared that i would forget her. that went on for months and months.
ive no advice as to what to do about that - i personally didnt want to do anything at all about it - i really didnt WANT to be happy at all, as i felt so strongly that i shouldnt be. which of course is nonsense, your dad wants you to be happy.
Theres no way that you 'should' feel. People cope with these situations very differently, you just need to go through the motions.
As for a school trip.. if i was in your situation i would refuse point blank to go, there would be no debate or question about it. my view would be one of 'screw the exams' to be quite honest. no matter how 'important' they are. & i would tell that to my teachers as my reason as well.
id just hate to think that someone i love had died in my absence cause i was off on a school jolly knowing that it could maybe happen - hell i feel bad enough about it happening when i had no way of knowing or stopping it and iwas in the same house with them when it happened because i didnt go to hospital with them or visit them after they died - something ill feel guilty about and regret forever. i cant imagine how i would have coped if id been on a school trip at the time.
And you have to stop talking about 'excuses' - you are NOT using your dads illness as an excuse, it is a REASON. and there is a definate difference, you havee to remember that.
and hun now is not a time for grief, its a time for hope - your dad is still here - spend as much time with him as you can, fit in your work for your exams around that, your dad is far more important, obviously, and the exams are not going anywhere.
i hope your dad gets better
stay positive while you can xxxxxx