Mine blue pea got tonnes of flowers, put fertilizers. Speaking of trim, i just simply trim weekly. Cut whatever I think out of shape.

I get those organic fertilizers from the flower shops. They did have those lamb/goats' poo. Besides, I make my own fertilizers. I got some place where i put the dead leaves and some soil. My wife and I always kept those vegetables's leftover during cleaning/washing. Boiled it for 5 minutes and dump at the same place. Did you water daily? It is hot weathers few weeks ago. Only couple of days recently rain.

I just trim the new parts to avoid overgrowth to other side since mine quite bushy. Some vines I pull downwards to cover the area seems vulnerable. I am not expert. I cut when I am free or I think the flowers are overgrowth.

I am not expert, most information found on the net. My family is vegetarian, so we got leftover from vegetables, fruits and eggshell. That's all.
Speaking of compost, I boiled my fruits cause it attracts flies outdoor. So, I boiled it and buried in browns (weeds, leaves etc). Another is the I got the 5L drinking water bottle, stuff with fruits skins, and vegetables. Add more oranges and lemon. Need add brown sugar. Leave it for a year. Basically, my house got mixture of ways to use the leftovers.

Compost

Fertilisers by using eggs, banana and coffee beans (starbucks can get free I think). Not Starbucks lover but heard you can get for free. Never try.

Homemade Compost