I worked very hard to bring three villagers to an empty ocean monument for an iron farm, and as soon as I turned my back, I got a zombie raid which killed one and turned the other two into zombies. I cured the remaining two and gave them some food but they wont pick anything up. I checked on the other reported issues and found mc-74407, which said it was supposed to have been patched in 1.14.3. I am playing on a realm in said version and I am having this issue. I don't know if this is being caused by a different issue or if this is something new, but it is still an issue in 1.14.3.
After further investigation, I found out the reason fot the problem. The server I play on has mob griefing disabled, which includes, apparently, picking up items. I set mobgriefing to true, and they were able to collect food and breed like normal. Thanks to all the mods who investigated this issue and sorry for wasting your time with my mistake.