You are in a difficult situation. The general feeling among swingers is the couples relationsihp has to be rock solid ebfore swinging will work. You wife has some issue, that I don't think either of you know about yet. I'd say seperate sexual experiences would be a step towards the end of your marraige. I fear swinging might be also.
Might be interesting to explore what her sexual experience was as a child a before she meet you. I'd say it would be goood for her to talk these things thru with a good councelor.