Losing Hope

So today I have been doing some thinking, some research and I'm starting to lose hope on getting pregnant. I've been pregnant twice before both miscarriages, the first one was in high school had no clue I was pregnant and the second I found out I was then I lost it, both with my now fiance. We have been trying to get pregnant for a year now, well trying but not forcing it ya know. I think back to my miscarriages and of course they make me sad but they also Make me think what if I never get pregnant again. It makes it even harder when your 18 year old sister had a baby with no complications which I wouldn't ever wish complications on anyone or her for that matter I was happy for her but it made it hard. I thought I might have been pregnant this time, my Boobs hurt, they are swollen a little bit, I get naesous, I actually threw up for no reason one night, but then yesterday I got my period and it just demolished my hope. I know that I am not the only one who feels this way but I often when by myself think of this, I think will I ever get pregnant?, will I ever get the happiness I see in my sister's eyes when she looks at her baby girl? Today I have just hit a pow point I guess, I'm on my period yet my Boobs are still a bit swollen and they hurt and I have been getting very naesous as well, these little things I have never experienced with my periods so I researched and things like this can happen, I read that your body could not have enough hormones so you body is gonna do what it naturally does which is bleed like it does once every month but I feel as though I'm giving myself unrealistic and false hope. It's hard to talk to my fiance about how I feel because he brings up how he might be the problem and how he was hurt with the miscarriages so I don't want to talk about it because I know he was hurt by it to though the second time I got pregnant he was a complete ass hole but there when I needed him. I am not sure what I am looking for by posting this maybe just to vent, maybe for someone to tell me alot of women get this way but right now I feel as though I'm hitting rock bottom with my emotion, just mentally drained and hopeless.