sleeping in rock n' play?

Ok so I need some reassurance that I'm not a bad mom for letting my daughter sleep in her rock n'play at night. I know they say it's not a good idea because of the SIDS risk and it can cause a flat head if done to much but it is literally the only place she will sleep for more than an hour. I have mostly just been using it for naps but I'm exhausted. She's not a good sleeper at all and I have tried everything I can think of, she will only sleep for an hour max. I even let her sleep in bed with me and still only an hour. Even in the rock n' play she only sleeps 2-2 1/2 but I will take what I can get at this point.