Não se preocupe! In conversation, the context will always tell you which word is being used.
There are many words which sound similar in English, even to native speakers, but they're used differently. Here are some sentences:
I'm studying in London for a ............
I can't ........... the music.
I have a pain in my ........
Did you ........ the news?
My little son is a ........ old.
Isn't it obvious in which sentences have the words 'ear' 'hear' and 'year' in them? Don't worry if they sound similar to you. Remember - in the real word, we very rarely use words in isolation. There is always some context that will help you.
The ye-, he- and e- sounds are very distinct, and native English speakers definitely pronounce them differently.
For Fábio's list, I think the problem comes from expecting a "hh-" sound for all the words which have an R. In English, these are completely different sounds. Try closing your eyes and listening to the words on forvo.com. Don't use Google Translate; the speaker pronounces everything in a rush.