Should you opt for shaving, try the trimmers with length attachments. Use the 3/4" head and see how that looks and feels, if that looks too long for you, you can always use a shorter attachment to get in closer. Hairs falling on top of eachother gives the appearance of having more hair than you actually have so trimming can minimize the appearance of being so hairy.
Should you opt for waxing, find someone who has several wax choices suitable for different skin types and make sure to exfoliate once your post wax irritation is gone - buy an exfoliating back band with an exfoliating cleanser. Should you be prone to ingrowns, this will minimize it. It you wax every 6 weeks, you will think that the hairs are disappearing. This is actually true for most people who wax their legs and arms but since your back is the issue, those hairs will return so keep up with your waxing regimen.
And of course, there is laser. Sigh. Its expensive and disappointing for so many. If you continue laser, don’t have high expectations.
And then, there is electrolysis; slow but steady and if you keep up with your treatments, have the area cleared as quickly as possible, it will be the solution to your unwanted hair issue.
Or, you can do a little experimment.
Feel the shame and go to the beach anyway.
Feel the fear and take your shirt off anyway.
Know that your body is going to be more protected from the elements than your hairless counterparts.
And know this, there are women who are highly attracted to anything that represents testosterone - and you might find a partner who really really likes your hairiness.