OK So here is issue #1.
Bread Yeast: It can work & can make some great brews. Problem is it has a very low "flocculation". That is the rate at which yeast will clump together and fall to the bottom. It is hard to do that and a coffee strainer is not enough to filter all the yeast out. You probably had several hundres of thousands of yeast cells left over giving you that yeasty sour taste. You can make much better wine with proper yeast/nutrients/methode.... so on so forth. If you want a really great drink then surch this sight and read, read, read. If you want an OK drink with the ingredients you have already used. Then try this:
1 gallon of coconut milk (No Water)
2.5 cups of sugar
1tsp of dry active bakers yeast.
Put all that in a glass jug and put a baloon on top with a small needle hole poked in the top. Once a day for the first 5 days start out by slowly swirling the jug to release CO2. Once it no longer looks like it will blow up then take the baloon off and get a wire wisk in there. Whip it up as good as you can for about a minute and then put the baloon back. After that sit it in a dark place and leave it alone. The raisins will soak up liquid and when the raisins have started to drop to the bottom then you know you are ready to "Rack" off the yeast cake at the bottom. That may take 1 - 3 month. look up racking or siphoning wine while waiting. Rack the clear liquid to a new container but add in 1 cup of coconut flesh. Let that sit untill it can't get any clearer. Probably 1 - 3 weeks. At this step you can throw the wine into the fridge and that will help. Rack a final time into bottles or a new jug and presto, much better wine. This will probably be between 10 - 12% ABV and plenty sweet to keep it tasting like coconut.
This is very similar to one of my first brews. "JOAM" Look that up and compair. It is an Orage spiced mead made with bread yeast and it is pretty good.
A painting says a thousand words. But a painting while on good mead just looks funny!