Discharge smell.... tips please

So for several months now my boyfriend and I have noticed when we have sex it smells like (tmi) sick almost. Like a very pungent sour sicky smell.

I’ve noticed recently that it’s not only when I have sex that my general discharge often smells that way.

I went to the doctor around 2 months ago and had some STI tests done, all were clear, as were my boyfriends (which we both knew as we had them done at the start of our relationship, but my doctor insisted).

I then used some Bacterial Vaginosis gel tab things. This stopped the odour for around a week and it came back again. I used them again a couple of weeks ago and again it only stopped the smell for a week or so.

Any tips on how to get rid of it for good? My doctor is useless and the BV gel only offers a very short term solution, plus they are pretty pricey.

It almost puts my boyfriend and I off having sex and, well, it’s SO embarrassing. It’s definitely affecting our sex life.

Would LOVE any tips!!

Thanks x