Hey! They may not all have angst but I tried to choose the ones that may be a little bit "psychological":
http://www.mangago.me/read-manga/tasogare_outfocus/
http://www.mangago.me/read-manga/hishakaishindo/
http://www.mangago.me/read-manga/udagawachou_de_mattete_yo/
http://www.mangago.me/read-manga/chen_sheng/
http://www.mangago.me/read-manga/stay_gold_hideyoshico/
http://www.mangago.me/read-manga/veggie_channel/
http://www.mangago.me/read-manga/goodbye_lilac/
http://www.mangago.me/read-manga/circle_wang_zi_ying/
http://www.mangago.me/read-manga/boku_no_kareshi_no_sukinahito/
The last two ones are very soft but still good reads with the issues you're suggested:
http://www.mangago.me/read-manga/unriped_expression/
http://www.mangago.me/read-manga/jackass_sawatte_ii_tte_dare_ga_itta_yo/
shounen ai (or yaoi) which has angst and is set in high school. maybe there’s unreciprocated feelings, a one-sided crush or the issue of coming out/confessing which makes it a bit emotional? thank you :))