Trying after a miscarriage.

So this past month has been hell. My fiancé and I have been trying for a baby for a year now. One morning this past week I woke up to the worst cramps of my life. I couldnt get off of the floor and was throwing up from the pain. I ended up taking midol and passing out from the pain. When I woke up I was fine. I thought I couldn't be pregnant because I took a test the week before and it was negitive. I then continued throughout the day and woke up early the next morning and passed a peach sized tissue. I knew right away what that was. I'm a vet tech. I see blood clots every day. This was not a blood clot. I went to the doctors the next morning and my obgyn refused to look at the picture I took but kept going on and on about congratulating me on being pregnant and that it's normal to have cramps and bleed in the first trimester. I'm no doctor but I know it's not normal to bleed uncontrollably and not be able to stand up from pain and pass what I did. The obgyn kept going though. Sent me for an ultrasound and said there is no signs of you being pregnant so you must just be early along. No i don't have signs of being pregnant because I passed it already. She then sent me for bloodwork and my hcg levels were high. And she said she still thinks I'm pregnant. Well it would still show I'm pregnant because it just happened today. She still wouldnt listen. Then 3 days later told me to get more bloodwork. My hcg levels were 85% lower then what they were 3 days ago. Her response was we will send you for more blood work in 3 days. I never went. Instead I called a obgyn and she told me right away from looking at my tests and picture that I was right. Part of me blames myself because I didnt know and was taking my pain medicine for my knee injury and drinking and smoking still. But I didnt know. But now my fiancé and I want to still try. Part of me also feels guilty to try again. Since I think I had a large amount to do with the miscarriage even happening. Or that if I try again that I'm just trying to replace the mistake I made happen before and just replace it with a new baby. Idk I'm a mess and my fiancé just doesnt get it. He just wants to jump back in bed. And said it would have been way harder on us if we knew we were pregnant and lost the baby. And that might be true. But I still blame myself more. Hes been great support. Dont get that wrong. But he just doesnt understand. So I'd there any tips on trying to get pregnant after a miscarriage and how to cope after a miscarriage? Because right now I just feel like I caused it and dont deserve to try again. Even though that's all I want to do.