32 and in a terrible job UK

hi all, please feel free to give any advice - I feel stuck in a rut and any info would help. I'm 32 next month and in a sales job for a company I hate. no matter what I do I feel I'm failing, even when I achieve and do everything that is asked of me. I think my bosses think I strive under pressure but I don't...i cry at home to my fiancé almost daily! I want to get out of advertising sales (been doing this for 8 years) but I can't find a role that would take someone with my experience. my fiancé says I should quit and we'll work out the finances but I don't want to put that kind of stress or burden on him as it's a big ask. we are ttc and I wouldn't get maternity pay anyway as I've not been here two years (still 8 months to go). the pressure I'm under is not helping us ttc ether. I've been for interviews but they say I've not got the experience for the media planning and buying eventhough I've been in advertising sales for ages. Sorry if I sound moapy, I just feel very down and trapped in my current situation. any advice? X