I think you have to be clear in your own mind about what the purpose of the PTA is, in your particular school and what the target of the fundraising is.. both the monetary target and the subject of the fundraising.
Asking the same 15 families for money, over and over again could be difficult. However, you do have a small audience, so you could do polls about what people would like to have / do / help with.
I have always been drawn to events that build community and events that give people something that they would otherwise buy themselves but at a good price.
Eg, community picnic / bedtime stories for primary / disco
I am not a fan of constantly tempting kids with sugar but popcorn and tutti fruitti days are alternatives.
Negotiate a discount with local events (possibly tricky with 15 families..) but group tickets to the Christmas Panto, including a donation to the school.. eg if tickets are usually £20 per head but the group ticket is £15, parents donate £3 to the school.. you would probably have to agree this with the venue in advance. Negotiate a discount with the local butcher for Christmas Turkey, parents give a donation to receive the discount voucher.
What does the school need... new library books... invite parents / grandparents to come in and read stories to the students and donate cash to the library fund. You could draw a bookshelf or create a virtual one and add books as they are funded. Musical instruments... have a concert and pass around a hat. Host a Karaoke evening and charge people to sing. Parents evening out for all partners.. not just mothers.. quiz, local beer tasting, curry night.
When beeswax food wraps were a novel idea, I made these with a group of parents and made quite a bit of profit but that was a one off..
Look for outside sources of money / sponsorship (quite tricky but solicitors, estate agents, dentists etc might be willing to make a donation in return for having their logo on PTA communications. Matched funding emoloyers.
We no longer live in the UK and where we live, it is very common for local events to invite local organisations to run food stalls... I suspect the food hygiene rules are different.. so at music events, craft fairs, community fairs, the food stalls are run by the local sports organisations, schools etc.
And most of all... I would avoid the mindset of you funding things, you being responsible for everything and the screaming into the pillow mindset... find people who care and want to do these things with you.. if no one does.. find another outlet for your energies, there are plenty of people / organisations who would welcome your volunteering efforts. If you are happy to do it.. great... but don't allow the particilation of others to be a condition of your participation and don't allow the apathy of others to drain your energy. Think about what you need in terms of physical and emotional effort to run an event and if you don't get that commitment from others, then don't do it.