失意concentrates on emotion.It means that someone is feeling down. 潦倒refers to reality.It means that someone is living in terrible poverty.潦倒 is often useful with “贫困（poverty）——“贫困潦倒”.

失意 = disappointed

Hello!They both mean frustrated,but we use 失意 more often.And u can say I'm 失意潦倒!:)

Hey,They both mean frustratedthey,sometimes they are interchangeable.But in many context ,they are not the same means.we frequently use "失意",

The antonym of 失意 is 得志 which means “to achieve one's ambition”，so the exact meaning of 失意“ is failing to achieve one's ambition. While 潦倒 is used to describe the situation of someone who is 失意， such as live in poverty. 潦倒 often combined with 穷困 to make up an idiom “穷困潦倒” which means someone lives in poverty.