Seroquel XR "typically" helps more for sleep than straight Seroquel.

Saphris offers many people relief in Insomnia. I got very tired about 20 m ins after I took it, but it caused me to wheeze so I only took that 1 dose.

Abilify ...Some people say it helps them sleep

Ambien, Lunesta and the like are really all the same , Hyponotic's and they either work well or not at all.

I have been averaging less than 20 hours of sleep a week for 4-5 months. Push came to shove and I agreed to take Doxepin its a old school tricyclic antidepressant..Started it Friday night and I have sleep anywhere from 11-13 hours of deep restful sleep a night,,, Its been amazing , But I know there is a good chance that its could flip me right into a hellish Mania. So I have my eyes wide open, If I get a hint of psychosis I will drop it asap . Keep in mind I am currently on no Psych meds. So that might make a difference.

What are you doing in other ways to increase your ability to get sleep? Whats your sleep hygiene like?

No laptops,cellphones, tablets or TV at least an hour before bed time.
Are you eating a healthy diet? Can you cut out all processed food? thats helpful
Do you get enough exercise daily?
Do you journal?
Even if you can't sleep do you make yourself lay in bed for at least 6 hours a night?
Do you keep your room cool and dark?
Warm soothing showers or baths before can be helpful to wind down.
Hot tea can also be soothing.
Meditation
Mindfulness
Yoga
Essential oils , Lavendar is a great one.
Never ever Nap

Personally I have found that when I go to bed I just tell myself " Okay I might sleep or I might not. If I do YAY if I dont thats okay too " I will lay there and day dream.. Often just taking away the stress of " Will I sleep or wont I " outta the mix.. Sleep can come.

You cant force yourself to sleep .. All you can really do is follow a schedule go to bed at X get up at X whether you sleep or not, Incorporate all the sleep hygiene tools you can to give yourself the best chance of getting that elusive creature sleep to visit you on somewhat regular schedule.

I hope you find something that will help. Insomnia is just one of the lovely shytti parts of Bipolar everyone deals with. it sucks