Need some support

I will be married 2 years in August and I've been off the shot for 2 years...my husband really wants another child and I want my first one..we've been trying for over a year..Ik that's not a long time to some people but it is for me...he thinks it's easy just have unprotected sex..I haven't told him this but I'm getting really depressed..I feel like it has to be me since he already has 3 kids...he doesn't know I've been tracking my cycles and fertility window...I don't want him to know how sad I am...he's more sensitive then I am..so thought I'd vent to you guys instead...I'm in my fertility window and haven't tried anything yet..I'm going to go buy some preseed..any other suggestions