Hello Lian, welcome in here
To your question - you and your BF have only TWO possiblilities - either apply for
fiancee visa or marry in RP and apply for
EEA family permit as your BF is Polish nationality he is exercising his rights in UK as a citizen of EEA member state (Republic of Poland).
So in your situation I would see marriage option as the easiest, cheapest and possibly quickest route to join him in here in UK - depends on your circumstances.
Get married in Philippines, then you could apply for EEA family permit at UK Embassy in Manila - this has a couple of advantages over fiancee visa:
1) it is for FREE - unlike fiancee visa where your fiancee would have to fork out £ 585
2) processing of EEA family permit is much quicker at the embassy with current processing rate of 75% applications processed in 5 working days (1 working week) and total of 100% applications processed in 30 working days (6 weeks) - again unlike fiancee/spousal visa where current processing time is about 15 - 17 weeks
Obviously getting married in Philippines has its own complications in securing relevant documents from HIS and YOUR side and time complications as well. Suppose you can get a lot of relevant info about marriage in RP on this forum.
But if he is able (finacially and timewise) to stay in Philippines for the time required to get married the advantages of EEA fam. permit far outweigh any possible complications - for example you will be able to start working straight after your arrival to UK
And anyway - for fiancee visa you have to secure a lots of documents as well and spend a lot of money on top...
Hope this helps a little, good luck to you both