Need help , fighting with husband constantly

I have been married for a 1,5 years and we have been TTC for a year . Right after I got off the pill we discovered I have PCOS, which makes it harder for me to conceive. 
But the mail issue is that me and my husband fight all the time , sometimes we have really good days and when we don't fight we are so happy together. We fight for something stupid and then I don't want to have sex with him for couple days until I forget or stop thinking about it. 
When you want to get pregnant timimg is critical , and limited ovulation days that I have I should take advantage of. But what should I do if I don't talk to him at that moment or I don't want him ? We fight for stupid things mostly , me not wanting to eat spinach , him drinking soda, his sister leaving dog food on the dining table just lot of stupid things, and later   It just bothers me for days.