TTC FOR 2 YEARS

My fiancé & I have been TTC for 2 years. I've talked to coworkers about trying different things. My diet is awful & I smoke. I've been trying to stop but I'm in a very stressful situation with work & they say that can play a part. I've read articles about changing my diet & keeping my hips up. I just had my fertile cycle a couple days ago & we did it 5 times during. I'm really scared that this month is going to be another let down. If you have any opinions/stories about things I'd love to listen. I know that there's people out there who have been trying longer than we have. I just need some advice..