Like a
bird with clipped wings, you desire the freedom to fly, yet due to
years of suppression, you can't seemed to find the courage to seek
this very freedom.
You blame your parents for being conservative, on the other hand,
it's also partially because you obey and kept status quo.
I will not encourage you to rebel, but rather, I say demonstrate
actual proof - that you are capable of independence, if this is
what you really wanted, without running astray. Chances are, your
parents will never hand over your freedom unless you can prove that
you have seriously grown up.
Your parents are probably the paranoid parents, who are probably
overly affected by the news on how youth become delinquents because
they had too much freedom.
This is exactly what you must prove; you have to address whatever
subconscious fear they have and mollify them.
Once when you have worked that out, your relationship will readjust
accordingly.
And as for your health condition, you got to consciously take good
care of yourself, if you have yet to understand the importance of
it. You keep yourself healthy, not because of yourself, but because
of the people around you for if you truly love your woman, I think
the least you could do is to avoid putting yourself in a worrying
situation where she has to struggle emotionally to keep you (and
herself) afloat, should anything happens to you. 
Cheers
