I fear you will not find any tin in the game anymore. There used to be tin nodes, until update 12 (Helm's Deep), when the way lower crafting tiers were set up changed to the format of the higher tiers: only 1 type of resources nodes per tier. So, tin ingots can now be bought at suppliers in game, just look for them when you buy your other crafting stuff.
http://lotro-wiki.com/index.php/Item%3ATin_Ingot
I hope you didn't spend too much TP on those ingredient packs :/ As a suggestion, ask here or look on the wiki if you run into any problems in the future (;
Not all those who wander are lost
Evernight: Faratalath (120 Hunter), Dorthar (86 Minstrel), Tardaros (62 Captain) and many more