It sounds like you have a full plate, and anyone would be overwhelmed with it. School, a baby, a home, and an old man. That's a lot, and you should pat yourself on the back for being able to handle it.
You are forced to be the adult, because you have most of the responsibiltiy. Not to compare you with me, but I had my daughter when I was 18, and I was forced to grow up really fast, while my friends were out partying and being young, I was changing diapers, doing midnight feedings, and being a mommy. Even her father (I call him the donor), didn't do crap. I look back on it now, and it made me a stronger person, just like it will you.
Some men take longer to grow up than women do. It will get better, but it may take a couple of years for it to happen.
Stay strong and give yourself a pat on the back!!!