When I think of Alyssa's journey, it is typically bracketed by the last 5 years. It was on this day five years ago, in the middle of the night, we told Lyss goodbye as she was wheeled off to get her first double lung transplant. The journey began weeks earlier, throughout the entire transplant evaluation process and the move from Kansas to Houston, but for whatever reason, it's always been receiving that call that her donor lungs were ready that feels like the starting point for me.

Over the last five years, this date has carried a lot of significance. Alyssa typically posted about it with a thank-you note to her original donor, Deanna. Lung transplants are not cures for people with CF, but Lyss's first transplant felt like an opportunity to be excited.

But right now, I'm struggling. Everything she went through, the surgeries, the procedures to reverse rejection, the infections, the constant stress, it all feels like we have nothing to show for it. I feel terrible saying that, but it's true. I feel like I watched my sister go through hell for years, only for us to have a taste of hope, a taste of a life of normalcy – the thing I wanted most for my sister – only for it to be five years of a quality of life arguably worse than her years leading up to it.

See, the thing about hope is that maybe it isn't an infinite resource. Maybe it's finite. I'd like to believe with everything in me that we humans are capable of an unlimited amount of hope. Our letdowns have been devastating. It feels like every time we get a surge of hope that the letdown is somehow bigger than the last, despite our familiarity with disappointment. How do I find it in my heart to continue hoping, when it almost seems like forgoing hope for a better future would allow me an emotional sanctuary?

I'm scared of the future. I'm scared of creating more memories without Lyss. When I look at what we went through over the last five years, the thought of my future five years is alarming. I'm 24; it isn't irrational to think my health could deteriorate quickly, but with the advent of better drugs, it's also not out of the realm of possibility that CF could have effectively life-changing drugs come out. So do I remain hopeful that I can start to think ten years into the future? Do I start planning for the possibility of actually having a child? What happens if I start to get hopeful that I may finally have a stretch of several normal years, only to have my lung function decimated by a particularly nasty lung function? The thought of going against everything I've been conditioned to understand about my condition – it's terminal, progressive, painful, life-shortening – may not be in my future into my 30's would be paradise. But the thought of starting to hope for that, only to need a lung transplant and to go through what I watched my sister go through is a fate ten times more painful than the joy of the alternative. I fear the fragility of my mind of having to go through that disappointment.

Nearly two and a half months ago – 57.5 months after one of the happiest days of my life, her transplant – I watched my sister die. I watched as her heart rate spiked, only for it to beat slower, and slower, as her body desaturated, as her organs gave out. I have now been in the company of three of the people that I've loved most on earth as they drew their last breaths. I want to remain hopeful, but these types of experience have a nifty way of draining some of your youthful vibrancy. I realize that abandoning life is something I've contemplated far too much over the last two years and I wish to continue towards a future that is hopefully filled with happy experiences.

But the letdowns. Man, the damn letdowns.

I recall the last five years. When they fly by through my mind, they're accentuated by the best and worst memories, as our lives are defined by those. I recall watching my sister be wheeled back for two separate lung transplants. I watched as she was told, this last time, they had no options. I watched the hope dissipate from her face. In some ways, that news, the doctor then coming to hug her, the disbelief in the room as we realized that there was no timeline where my parents, Alyssa, and I would be together much longer, was the last day of Lyss's hope in life. She wanted to be evaluated elsewhere, she wasn't ready to give up fighting yet. I'm not sure if that was for my parents or my sake, or if she really wanted to keep living. She did not enjoy herself in LA and the fact that she looked so healthy in her pictures accentuates her life so well; she was able to present herself in such a beautiful manner, as her mind was the polar opposite.

I reflect on the happy times, and even those, for me, in retrospect, feel as if there was a gloomy cloud over them. Maybe that's because I know the end result, but I always felt as though rejection could be imminent. It made celebrating monthly milestones feel like we were drawing attention to the fact that we knew Alyssa would not get a lot of mileage out of those lungs.

Writing this piece makes me feel like a terrible brother and especially a terrible person. I feel like I've been pessimistic this whole time. But this day feels like the culmination of an unfair half-decade. I'm heartbroken in thinking about how hopeless I feel right now. I hate this disease so fucking much and I just want to feel normal. Lyss did not deserve the hell she dealt with and the legacy she left only serves as a constant reminder of her breathtaking strength.

I believe I feel this way because this weekend was the biggest reminder in two months of what the world lost when we lost my sister. Today was probably the hardest day in the last two months for me.

I feel hopeless in many ways but at least I'm hoping I can start hoping again.