Pregnancy Forum - Pregnant: Doc took me off Effexor- Now I'm self-destructive

I'm 23 weeks pregnant. My husband and I have close friends who have two small children, and we just decided in April that maybe having kids would be ok. I'm only 23, but we've been married 3 years. I've been on Effexor for nearly our entire marriage, and it helped me function. I'm self-destructive and pretty irrational when I'm not on my medication. When I found out I was pregnant, my doctor took me off of the Effexor immediately, so along with my morning sickness, I went through withdrawl. I was excited for the first few weeks, and then started getting apprehensive. I had to quit my job (I had only been there 1 month and a half anyway) because of the withdrawl. I was starting to feel like the medication was finally out of my system, and I was getting scared. In August things started looking better, and I felt like my mood had plateaued. I wasn't super energetic, and I cried easily, and really had to limit my exposure to other people (I get really anti-social...can't even answer my own phone), but I didn't feel like hurting myself, and I was excited about the baby.
This last week I've fallen apart. I feel like I've been faking it for the benefit of everyone else...friends and family. I'm not happy to be pregnant. I'm not excited about the baby. I'm terrified of childbirth, and of the huge responsibility...of being a mom for the rest of my life. I'm jobless, which really doesn't help. Plus, I'm having a lot of pain in my hips and pelvic area, so I can't stand for very long. I hate feeling the baby move, because I'm scared of change, and I don't understand what's happening to my body. (It's happening way too quickly!) Yesterday my instinct was to hit my abdomen when I felt kicks...I stopped myself, but it scared me. I've never thought about hurting the baby, and all of a sudden I just wanted it to stop. I wanted it out of me, and I didn't even want to see it.
I almost had a panic attack today when friends invited us over to watch our favorite tv show (which we do every week). I feel like I'm being pressured by society and I'm breaking apart. I tell my husband how I feel. and he's supportive, but he doesn't know what to do.
Now I feel guilty, because I thought I wanted this, and every day I scare myself more and more. I don't want this baby to exist, and I hate myself for even thinking that.
I think about going to the hospital, to the psychiatric ward, but then I'll be put on high dosage anti-depressants after the baby is born, and won't get to breastfeed. Which I used to care about. Now, I just don't want to even bring the baby home.
Does anyone know, at what point should someone admit themselves to the hospital? How "bad" do things have to get before it's a serious enough problem? (I'm scared to go in, that they'll just say it's no big deal, and I'm just pregnant and a little hormonal.)
I'm just so confused, because I know this isn't me. I just don't know where I went.