Complicated pregnancy at 6 weeks

So I went to have oral surgery on June 29th. Of course they do a pregnancy test to make sure you can have anesthesia. And of course it comes out positive. I’m shocked beyond belief, but happy at the same time, but more shocked then anything to the point where i had them retest me 3 more times just to be sure. Because clearly, one wasn’t enough proof. I tell my husband I’m pregnant in the dentist office, because who doesn’t want to know this way. So I’m excited he’s beyond excited. We go home and make an appointment with the OB. We go to the appointment the following week on a Monday for the 1st exam. The set my due date as March 13,2019. Ok, we have a date. I’m over the moon. It’s becoming a reality. Wednesday rolls around I’m at work. I begin to bleed. I contact my husband who told me to contact the OB so I did. They instructed me to go to the ER. So I go. I’m bleeding like someone murdered me. I’m thinking this is it, no more pregnancy. They send me for a vaginal ultrasound and say the baby is still there and measured at 5 weeks and 4 days but to soon for a heart beat. I have a sigh of relief. The bleeding finally slows and they release me to go home. I call my OB to make a follow up appointment. They want to check my labs and do an ultrasound again. So a week after the ER I go in for my follow up. There’s a heart beat. It glows like a beacon in the ultrasound. I’m beyond moved and feel a tremendous pressure released from my chest. Then the doctor comes in and crushes my world all over again. She states the baby at ultrasound a week later only measured at 6 weeks and 1 day, so it’s not growing the way that it should. Then proceeds to tell me that my HCG levels while in the hospital were 7,312 which was completely normal. But when I had the new blood draw a lot only increased to 10,370. This should have doubled at that point and it had not. Finally she said it is a viable pregnancy at this point, but the heart beat was only 118 and it should be in the 160s. So the future currently looks bleak. I’m trying to stay positive. I feel like Ive failed my husband because he is so excited for this. I go next week for another ultrasound yo see if there is any improvement. If not I have to discuss the real possibility of having a d&c.; I’m such a strong person normally, but I just feel crushed and lost and overwhelmed like it’s my age (which I’m 37 and this is my first) or something else I’ve done. I just need an end to this one way or another. Good or bad. I’ve been giving more questions than answers. Thank you for letting me vent.