Nursing Strike?! 😔

Any of you breastfeeding ladies have any tips on how to get your little one to *want* to breastfeed again?? 
My 3.5 month old was breastfeeding for the majority of his feedings and we would supplement a bottle of formula at night sometimes (I try to pump but I get less than an ounce everytime, it seems to only flow when my baby is attached). Well as of about 4 weeks ago he is always refusing me or only staying latched for 5 mins max! I read about nursing strikes but this just seems like it's lasting forever and he's starting to prefer the bottle. If I could pump, this wouldn't be a problem but... 😔Â