Struggling

I'm a new SAHM with a three month old daughter. I love her so much, but she is definitely what you would call a "high needs" baby. I seem to be the only one who is able to calm her down and keep her relatively calm. I am exhausted. She doesn't sleep well at all, and I have to hold her for her naps during the day. It takes a lot of walking her around to get her to sleep, so my back and neck are killing me. The hardest part is that there is no end in sight. I've made peace with the fact that I won't be able to go do anything on my own or with just my husband for a long time, but I thought I would be able to go places with her by now. Every time I try, it turns into a meltdown. She hates being confined in her car seat or carrier. She will eventually fall asleep in her car seat-- but short naps just make it harder for her to fall asleep later, and she gets overtired easily. I thought I would be able to do something as simple as walk around the mall with her by now, but I don't see that happening any time soon. I have a couple of friends who are stay at home moms near me, but I don't feel comfortable bringing her over because she just ends up screaming and we can't have a decent conversation anyway. The only break I get is a shower, and even that can't always happen if my husband works late. I guess I just needed to get all of this out. Has anyone else been through this? Any tips on how to cope? I just want to be at my best for my daughter.