I'm not sure I understand the exact question here: is it "what is Winston's idea's of love?" I'm not sure what the "suffering" added on at the end means.
In 1984, Winston is not meant to love anything except Big Brother. The totalitarian state requires unconditional nationalism, and they watch and torture and lie to their citizens to make sure it is achieved. Families are destroyed. Dating is prohibited. Marriage is only condoned for procreation purposes only.
At the beginning of the novel, Winston begins to love rebellion: "Down with Big Brother" he writes in his secret notebook. Later, he looks to O'Brien and Julia as competing allies in his thoughtcrimes against the state.
At first, he finds physical love with Julia. Their sexual encounters are, according to Julia, "rebel[lion] below the waist." Though this is eros (erotic love), Winston's relationship with Julia is love nonetheless.
But, when O'Brien baits Winston into loving rebellion against Big Brother, Winston forsakes Julia and reverts back to his original, solitary love of political rebellion.
Obviously, this love against the state is a trick, and Winston is tortured into forgetting all about Julia, his mother, and his former identity. He becomes an unperson with nothing left to love except the glaring face on the posters plastered around the city.