OMG.

Google "modest swimsuits", "vintage swimsuits", "swimsuits with skirts", "beach coverups" and "sarongs".

Then, search for all of those terms on Amazon as well, and possibly on Zappos.

Then, select what you like, compare the prices and find out about the return policy.

It is 2014, my goodness - anything that you can possibly think of is offered for sale by someone, and things you cannot possibly think of are also offered for sale.

Another option is ETSY and there you can custom-order by giving a seamstress your measurements.

This is all according to your stated preference for the feminine style.

Another option altogether is a surfer's style - a rashguard which is basically a long, long-sleeved shirt plus shorts.

The surfer's style has its advantage in terms of summer safety - usually these things are made from UPF materials (UPF in a fabric is like SPF in sunscreen).
With swimsuits, it may or may not be the case - you have to check carefully.

Another GREAT option that is BOTH feminine AND summer-safe is ordering from a company called Coolibar which was recommended by my dermatologist.

Take a look: a maxi white skirt that would look casual and chic and not reveal your internal insecurity:

Maxi Skirt: Sun Protective Clothing - Coolibar

And this is a compromise - naked shoulders but the rest is covered.

Pareo Cover Up: Sun Protective Clothing - Coolibar

Note that if you wear a bikini, you would not look like a temptress - you would look like an insecure girl who feels awkward wearing a bikini. The opposite of a temptress.