Am I stuck in an unhappy marriage or is it just in my head?

I don’t know how to address the issue I have. Let’s start with some background about me and my situation; my wife and I have been together for 22yrs, married 19yrs. For the most part things have been good, we have a lot in common and make each other laugh, and have a son together. The problem is that I suffer badly with depression and low self esteem, which I can never seem to be able to discuss with her. She doesn’t seem to handle those kind of things very well. I’ve had episodes of low mood before but it never seemed to be a problem until 5 years ago. As 2014 started I had a particularly hard time, I hated my job and I spiralled down very quickly, to the point of contemplating suicide. In the end I was given redundancy by my employer and started again, but that’s when the first cracks appeared. It seemed that my wife didn’t trust me anymore, it felt as if she was blaming me for loosing my job and putting a strain on our finances. I fully understand that view, but again she wouldn’t talk to me about the situation. At this point a wedge was put between us, and we stopped being intimate. In fact she seemed to withdraw all affection from me, not even saying ‘I love you’ anymore, which we did every day before. As 2017 started, things were better; I had been in my current job for 18 months and even though I had gone through another episode of depression, it had been resolved quickly. Unfortunately I then developed a serious back problem, which resulted in two surgeries and has left me with chronic pain and weakness, which I am trying to address through exercise. As a result I have been off work since January ‘17 and have yet to return. As you can imagine my mood has also nosedived, but I am engaging in counselling for that. As a result of these last 5 years, my wife and I have had an entirely sexless relationship, it feels more like I’m living with a friend rather than a lover, and broaching the subject feels impossible due to how difficult it is to talk to her, and because of how long it has gone on. This has all led to me feeling lonely and trapped, with no clear way out. What is the best way to approach this problem?