You are still early in he game and you have not discovered new areas, techs, etc etc. Just find an other source, build a miner and slowly continue to expand till the moment you feel the miners produce more then you can handle. Add more machines in the chain etc etc, and at some point you can automate the items needed to unlock the tier. and don't worry, next tiers need more items and complex items. It is supposed to be not that easy.
What you also can do is (like what I did) pop 10 portable miners on 1 source and hook up a container to a smelter (or more) to a container. This way you get like 1000x raw iron that you can throw in the container and will be smelted. It is partially manual and gathering resources is way faster then having 1 miner on the source.