Meaning of "if only because"?

Hello everyone. I am reading a novel, and I came across this expression. Could you please let me know its meaning?

As I loitered about the park and looked around me, I knew I didn’t mind the sorrow, didn’t mind the loss. I loved lingering in her park, liked the snow, the silence, liked feeling totally rudderless and lost, liked suffering, if only because it brought me back to last night’s vigil and enchantment. Come here as often as you please, come here after every one of your hopes is dashed, and I’ll restore you and make you whole, and give you something to remember and feel good by, just come and be with me, and I’ll be like love to you.

- André Aciman, Eight White Nights, Second Night

This is a novel published in the United States of America in 2010. This novel is narrated by the nameless male protagonist who meets Clara at a Christmas party in Manhattan. On the night after the party, the protagonist is walking around the park, thinking about Clara.

Here, I wonder what the underlined expression means.Actually, "if only" appears several times in this novel, and, in case this might be helpful, another instance is like the following:

And just as I was beginning to believe it, I knew I was lying to myself. I’d come back tomorrow night, and the night after that, and after that as well, with or without her, with or without Rohmer, and just sit here and hope to find a way to avoid thinking that I’d lost her twice in two nights, sensing all along that hers was the face I’d put up around this park to screen me from myself, from all the lies I round up by night if only to think I’m not alone at dawn.

Thank you very much for your help.