You need to make the second letter of "suggest/suggestion" sound less like the "u" in "bus" and more like an "uh". Don't change your mouth shape at all between the "s" and the "gg".
With "quest" and "question", you pronounced the "e" like an "i". They sounded like "quist" and "quistion".
Have you checked Forvo.com? It's great for listening to native speakers say individual words.
Here's the page for "suggest". There are 8 recordings there, from a variety of English variants. You can change the word in the search box to find "suggestion", "quest" and "question".