Am I truly happy?

Lately I've been reading and watching plenty of self help, motivational, and inspirational videos and books. My regular attendance at the free clinic in Jalan Pudu on every first weekend of the month is in fact, a form of self therapy, a reminder that no matter how bad my life is, there is always someone out there who lives a harder life.
I know I don't have to be what people said I am or should be. Ultimately, it's I who dictates who I ought to live my life.
No matter how hard I try to ignore all the negative remarks thrown at me, everyone has its own limitation. I am one person who constantly gets negative remark from my own flesh and blood. No matter what I do, the negative impression has already being embedded in their minds. That I am the black sheep of the family. It doesn't matter that I've donated more than RM30k for charity, regular quarterly donation of blood to a Thallesemia Major child for 4 years while in university, that I helped to set up a school whilst studying in India for the poor and unprivileged children, but all of these were done without any knowledge or whatsoever by my parents.
This post is written as an expression of my penned up feelings after I had a talk with my dad this morning. I am constantly being compared to my siblings, who are financially stable, with fat bank accounts. Unfortunately, in my family, a fat bank account equates success in life. Needless to say, therefore to their eyes, I am a useless son.
After I found out that my dad has cancer, each time I spoke to him through the phone, my heart melts, and the sadness was overwhelming. I would shed tears, I would cry whenever I speak to my dad. My mum on the other hand labelled me as useless and weak for shedding tears whenever I speak to my dad. I simply couldn't accept the fact that my dad is dying.
Shouldn't she instead label me as useless if I sound happy and laughing away each time I speak to my dad when I know his prognosis is grim?
My children aren't spared as well. They are constantly being compared to my sister's children. They've complained that the house is messy, filled with toys, and they were actually pissed when they say the two terrapins that I got for Isabelle.
Aren't grandparents supposed to love their grandchildren more than their actual parents do? Why is my family being the exception?
Why are they being skeptics on my transformation. I've changed for the better. I am a health freak now. I used to be obese, lethargic, basically unhealthy and very unattractive to look at. After losing over 20 kg, today, i cycle 30km daily, and would lift weight for 2 hours without missing a session for the past 4 months.
My therapist sees the transformation in me. He questioned me why am I punishing myself? (which he though I was) but in fact, I became addicted to being fit and i've never felt any better than this.)
He actually asked me whether am I planning to join competitive body building as I did during my university years.
If an outsider can see the transformation within me, why can't my own parents see that? This is the main reason, perhaps the only reason for my unhappiness.
I know I am done trying to prove myself to my parents. Only God and my wife knows and understands me. That would be enough for me.