In water drop situation you shouldn't put your phone in side rice. You need to quickly open inside the phone and plug off battery connector then dry the inside of phone with cloth (should be microfiber cloth so it suck up water fast) then wait about 12-24 hour and reconnect the battery connector the try turn on the device.
Ps if you put phones in rice, rice will make the inside rust and will cause perniment motherboard broke so you need to buy a new one.
In your situation right now you need to get inside the phone then dry it with cloth to not make it rust and you can use it normally.
But about cydia and tweak isn't work I don't know what happen because there will be software and hardware so your phone boot up then your hardware isn't broken and if normal iOS runs normally then your software isn't broken in this situation you should rejailbreak it (restore but from your current iOS by downloading .ipsw on this www.ipsw.me just don't care about unsigned because in your device have shsh blob for your current iOS) after restore try jailbreak from your trusted tools. And see if it works.