helping the strays and ferals

ive been helping strays and ferals for a long time now it seemed to be working fine they grew in time to trust me and i give them so much love recently things have changed people have been deliberately running them over and in the last few weeks i have suffered where 4 have been poisoned they came back to me for help but i couldnt not save them i am heartbroken and didnt know what to do my vets bill went through the roof but that did not matter all i wanted was them to live but unfortunately that didnt happen in totally 5 have been poisoned biscuit lilly bear fi and felix 1 was run over titch and 3 over the years are missing belle little lil and smudge although i have never stopped looking for them in my heart i know ..im hoping to get help in buliding a safe place in my garden to put the rest of the cats into so they can still be outside but be safe at the minute im fighting a losing battle trying to get them in the house to keep them safe they are not used to being inside all the time and i feel a large shed and very large run would help them i hope you all can help and stop anymore getting hurt this is my last option