How can I move on after death of my only child

[PainMiddleName]

Hi everyone. I'm new here but need some advice & help moving past the death of my 4 month old daughter. It's been 21 years and I still can't move on. I only held her hand full of times, she never left hospital, survived 10 operation before doctors told us that it was a matter of days & suggested that for her sake we take her off life support. We took her off and I held her & told her that it was ok to let go. From there it's a weird haze. 2 days later while out w/ my family trying to find a place to lay her to rest, we we rear ended by a semi that almost took my life. I live not only with this giant hole in my heart but also chronic pain from a very messed up spine. Doctors say that the accident & pain from accident have crossed wires "so to say" in my brain/mind that it's making it all the harder to move on. Can anyone help me or give me a direction to turn to?  I've been hospitalized for having a full blown mental breakdown to where I've been told by husband I couldn't speak, eat, walk or anything else w/o his help. My eyes were open but he says that there was no one looking back.
I suffer from PTSD, Clinical Depression, agoraphobia, panic attacks, night terrors, bipolar disorder and sleeplessness <due to head trauma/brain damage from accident. I've seen so many doctors, tried almost everything out there & still I'm stuck as if it happened yesterday.  
I've not been back to her grave but once. I feel like such a failure, daughter had birth defects even though I quickly stopped smoking the night we found out we were expecting, I didn't drink and watched what I ate. Nobody even mentions her at all & that kills me.
I'm not in a situation where I would harm myself as I believe that if there is a better place our souls go, I have to keep that belief, I want to be reunited with my baby girl. It's been 21 years for crying out loud.
Help, Please.  
Thank you for your time, any advice & any guidance.

[PainMiddleName]

AnniBrooke,
     Yes, as of This month it's been 21 years of constant pain & struggle to find my purpose to still be here while all I want is to be w/ my baby girl. My husband and I are still together. Which from all I've learned from therapy & read books is beating the odds. However he won't say her name or let me grieve on 2 certain days of the year, birthday & day we took her off life support. Yes, been in therapy off & on for the past 21 years, been hospitalized a few times due to my depression and PTSD. I have a dog & a cat, that's as much as I can physically handle due to chronic pain and spinal injuries. I am house bound except when I have to see Drs and go to physical therapy. My husband would never let me work with Friends of Strays or anything else.  It's like by not even saying her name my husband can just block her out. For me it's sorta like taking her from me all over again. If a tear excapes when talking about her, is not so much from sadness then from joy that she is alive in memory. If you can make some sense out of that.  
I'm a fighter, always have been but it's getting harder w/ only 1 friend left and
Thank you for your advice and kindness.  

[AnnieBrooke]

It has been 21 years with this level of pain?  And your husband stuck by you all this time?  What is your daily life like, are you housebound?  That would be enough to get someone down in the dumps all by itself, without the whole catalogue of terrible happenings that you went through.

But stuck is stuck and you really are kind of sick and tired of being stuck.  I assume you've been in therapy all this time?

My suggestion is to start with tiny, forward steps, deliberately starting small, if you are housebound especially.  Perhaps foster a litter of kittens for a humane society, which is something that is simple, takes you being attentive to do successfully, contributes to the world, and is rewarding.  Even if you never get farther in activities than to play with kittens and send them out to new homes as happy, active young cats, that is a better thing to do  than staying in a stuck place.  It won't take the place of the life you lost, but it will mean you are not crying all the time.  Try something like that, if you don't care for cats, try another place that has this kind of need, fostering animals is rewarding.