Can anyone suggest a manga/anime about a loner(like sawako from kimi ni todoke) or a person who doesn't need friends(like the main character in say i love you and my little monster) but will also make friends at the start or the middle of the series

What i have already watched:
Kimi ni todoke, my little monster, say i love you, and one week friends

Tonari no Kaibutsu-kun
Cat Street
Warau Kanoko-sama and sequel Koi Dano Ai Dano

I can't say I've read an awful lot, but I can definitely think of two that fit the bill:

Sangatsu no Lion. Although technically Seinen, it's the kind of masterpiece which can be appreciated by all audiences, provided one is willing to accept the shogi and the relatively slow pace. It's all about Rei coming out of the lonely depression he's been in, quite frankly, his whole life and the process of him being shown several kinds of warmth by the three Kawamoto sisters. Loads of awesome, lovable characters and their development. I also recommend the anime, as it's got one of the best adaptations I've seen. It can be incredibly heartwarming if you give it a chance.

Natsume Yuujinchou. Another gem, this time Shoujo, it stands out amongst its peers for once, by having absolutely no romance - and it won't need it to warm your heart. Orphaned at a young age and passed from relative to relative with the often malevolent spirits he's always seen written off as hallucinations, Natsume has always been viewed as a trouble-making weird kid by society. He never managed to stay at one place for long. By the age of 15 he's learnt to keep everything to himself - when at heart, he's a gentle and responsible soul who merely wishes for a place to belong. Long story short; despite the episodic nature, it's very good with great character growth. The anime is also good, and to be honest, I've only seen it, not read it as of this date, but it's still an all-time favourite.