It feels like our marriage is breaking up and I am now finding my wife physically unattractive - is there something wrong with me?
Things about her that didn't used to bother me now do - like how she doesn't always enunciate words, the tone she uses sometimes in innocuous things she says (just the way her voice sounds at times). I'm starting to think that she should be with someone who truly appreciates who she is, but the last thing I want to do is hurt her. Is there something wrong with me? This is the first "healthy" relationship both of us have ever had.
You are fighting with your wife and this fighting is leading to feelings of separation and then antagonism. This in turn manifests in negative feelings towards your wife's personal details. There is nothing unusual in that. Put aside your antipathy toward your wife's appearance and speech and instead focus on your heart connection with her. This connection has been damaged by your own anger which you are projecting outward toward your wife.
To stimulate your heart connection I want you to give up seeing your wife as someone you need to oppose. Start by apologizing to your wife for having been repeatedly angry towards her and tell her you are making a fresh start. Then completely desist from defending yourself and your point of view in conversation. Give up entirely your need to be right. Replace these defensive postures with their opposite - a desire to listen to and understand your wife.
You will receive help with this if you focus on your wife's needs and not on your own. See your role of husband as that of someone who serves and supports your wife, by listening to her, being aware of her moods, anticipating her needs and doing all sorts of small things to meet them without her having to ask. Do this even if you do not feel like it and stick with it. Do it willingly and with a good heart. By listening, being understanding and attentive and by anticipating and meeting your wife's needs you will diffuse all antagonism.
Such an approach will reconnect you to your wife's heart and all fighting will cease because your wife will have nothing to oppose. When your wife finds she no longer needs to oppose you and knows by your actions that she is understood and valued, she will be open to falling in love with you all over again. When your wife falls in love with you again, you will start to have your own needs met without the necessity of having to ask. When this happens you will experience your wife as the most beautiful woman in the world.