I don't think it's the slightest bit selfish to want more than 45 mins break!
Tracy's EASY routine and the reason why many of us are here is based on realising that 45 mins just doesn't give us the time or break we need so we can shower, eat, nap, breath. It isn't selfish, it's just that there are certain times or phases with babies that it's not always possible and you are in one of those phases. Hang in there, you will get through this.
It might help to know that very many of us have gone through tricky and exhausting times with our babies, that's why most of us found our way here to the forums. You are not alone x
Comments about trying to "let it go" are intended purely in a supportive way, that sometimes getting wound up or too focused on the routine or nap lengths can drive any of us a bit insane. Sometimes it helps to "just accept" the rubbishy naps and get on with your day so you are not stuck in a darkened room shush/patting the day away, feeling exhausted and also resentful that the day is passing you by. One of the things I did during this difficult phase was use the 40 min nap to prepare a bag to take out - I had to bomb around the house to do so, get the milk, the nappies, a bottle of water and a snack or lunch for myself etc etc, and then I put the sling on and literally stood by my DS cot from 35 min waiting for him to wake up. At 40 min on the dot he woke and I put him directly into the sling, walked down stairs, picked up the bag and walked out the door. I knew I had 1hr 40 before he had to be back in his cot and in that time I drove to a park, fed him there, ate my lunch, looked at trees, breathed fresh air, changed his nappy and drove home.
Sounds like a lot of drama but it was worth it, his mood was good when we were out (although he refused to sleep out and about) and mine improved. This is an example of "let it go" and accepting the short nap and doing something nice instead of stressing over yet another short nap.
But do not say you are selfish - no no no!