I feel like a bad mother

Baby girl is 4 months.  We just moved her from pack and play to crib, and it's been a nightmare.  Last night she was up four times.  She will only nap on the crib for 30-40 minutes. I used to let her nap on the bed and she would sleep 1-2 hours, but she's close to rolling over so I'm breaking the habit.  I'm so tired, and I'm tired of the fight.  We are only on day 2 of crib napping and I know I can't give up.  I'm off for the summer, and this just isn't fun at all.... I don't want to spend the summer teaching a baby how to nap in the crib, sleep through the night, etc.  it's so tiring.  And hubs isn't home from work until 7:30, which is when she goes to bed.  Ugh this is depressing. I'm so thankful for a healthy baby, but does anyone else feel like this? I'm so jealous of women who say their babies sleep for 2 hour naps in Their crib and then sleep 12 hour stretches at night.  I feel like we will never get there.  Please tell me there's moms who feel the same