Help!

Im so stupid idk why I didnt wash my plants from the local fish shop and now I have ich what should I do all my rummnose died in a day while while I was at work and somehow I didn't notice until now they had white spots my other fish don't have a lot of white spots but some are starting how do I treat them with no harm to plants and snails? BTW idk if plants can bring ich or just fish so don't come at me lol idk what else it could be since I haven't added anything else