She might grow out of it. (Teething, developmental changes, "this too shall pass," blah blah blah
) Are you trying lots of different things? There were times when my dd would only sleep in the sling, or when I needed to make sure to keep her in the same room with me. (There are different reasons for the latter thing: In a baby of a certain age, it can be stressful to wake up alone, so they start fighting sleep. Once they realize they are going to stay safe near you -- reassured by the sound and movement -- they can let go more easily. Another reason is that you can easily see the first sign and intercept waking up with a hand or picking up/moving/rocking or whatever works for you before your baby is fully awake.) There were other times when my dd would only nap in public or on a train or being walked briskly in the sling, or being walked up and down stairs or bounced by daddy. Movement was a big thing for her, and the cause of most sleep problems she had. Once we figured that out, she responded amazingly well to wild play (e.g. tossing up in air, dangling by her limbs, walking her up and down our bodies) and massage when she started seeming tired. After the play and massage, she would nurse right to sleep. Other movement things: Wild dancing or other very vigorous movement with baby held or slung close to your body (being careful not to shield her from the movement), walks, I've heard car rides (don't have a car and dd hated the carseat, though).
Another thing that I've heard a lot of -- and that worked to a limited degree with dd -- is being careful not to miss signs of fatigue. If a baby is ready to sleep but for some reason not in a situation where s/he gets what s/he needs to fall asleep (this could be as simple as, baby doesn't cue and you don't notice and you don't happen to be doing something that helps baby fall asleep), s/he can shift into overtired mode rather quickly. Then it becomes hard to fall asleep. Some babies have strong internal clocks that don't match their parents'. I've heard of natural bedtimes as early as 5:30 pm. (??!! - I can't imagine how painful this must be to live with...) Or sensitivity to light changes. For example, needing low light around the house to fall asleep in the evening. Or being unwilling to go to bed until the whole family does! (My dd did this at some times, too.)
To make sleep "stick" with dd, I found I had to work hard to keep myself from getting impatient. If I spent plenty of time nursing her, let her unlatch spontaneously some time after she appeared to be asleep, and then waited until her limbs were completely limp (up to 20 min after the initial eye-closing), she tended to stay asleep longer. I guess she needed to get into that layer of the sleep cycle, or she might notice that something was awry and reawaken. (It sounds awful, but I always think in terms of getting a baby to sleep out-of-arms being trickery. I believe many/most babies' natural sleep functions seem to be built around the assumption that a warm body is going to be there at all times.) When I wasn't trying to trick her out-of-arms, a 10-min nap was not always a bad thing. They could happen several times a day, as long as I was keeping the movement going.
For a little while dd napped well in a reclining umbrella stroller. Sometimes she napped better lying down on a bed or floor, sprawled out. Sometimes I needed a piece of furniture with a back, so that she could lie on her side facing it (another mama substitute trickery strategy
: ). I've heard of babies who love hammocks.
Maybe none of this will work for you, but you can't say I haven't fleshed out what I mean by trying lots of different things.
Hope your dd starts sleeping better soon. It sucks to be tired.
Another thing that I've heard a lot of -- and that worked to a limited degree with dd -- is being careful not to miss signs of fatigue. If a baby is ready to sleep but for some reason not in a situation where s/he gets what s/he needs to fall asleep (this could be as simple as, baby doesn't cue and you don't notice and you don't happen to be doing something that helps baby fall asleep), s/he can shift into overtired mode rather quickly. Then it becomes hard to fall asleep. Some babies have strong internal clocks that don't match their parents'. I've heard of natural bedtimes as early as 5:30 pm. (??!! - I can't imagine how painful this must be to live with...) Or sensitivity to light changes. For example, needing low light around the house to fall asleep in the evening. Or being unwilling to go to bed until the whole family does! (My dd did this at some times, too.)
To make sleep "stick" with dd, I found I had to work hard to keep myself from getting impatient. If I spent plenty of time nursing her, let her unlatch spontaneously some time after she appeared to be asleep, and then waited until her limbs were completely limp (up to 20 min after the initial eye-closing), she tended to stay asleep longer. I guess she needed to get into that layer of the sleep cycle, or she might notice that something was awry and reawaken. (It sounds awful, but I always think in terms of getting a baby to sleep out-of-arms being trickery. I believe many/most babies' natural sleep functions seem to be built around the assumption that a warm body is going to be there at all times.) When I wasn't trying to trick her out-of-arms, a 10-min nap was not always a bad thing. They could happen several times a day, as long as I was keeping the movement going.
For a little while dd napped well in a reclining umbrella stroller. Sometimes she napped better lying down on a bed or floor, sprawled out. Sometimes I needed a piece of furniture with a back, so that she could lie on her side facing it (another mama substitute trickery strategy

Maybe none of this will work for you, but you can't say I haven't fleshed out what I mean by trying lots of different things.
