Hope this helps you , ( I read your thread and was very sadened to hear you have been through such unhappiness , I don't classify my self knowing everything about sikhism ( more the opposite ) or even put myself in your shoes , I just thought I share the little knowledge which may or may not insert Wahegurus Faith backi in you)
you can try :-
1.listening to Kirtan alot
2. Go to gurudwara everyday , or more often , and when there share your feelings with Waheguru
3. listening to katha , and understanding it ( I found Bhai Ranjeet Singh Dhadrian wale katha , very effictive) its simple to understand
4. Reading sikh scriptures inspirational sakis , the history of the gurus etc.
5. listen to Radio if your in the UK evry vaskahi and on siri guru nanak dev jis birthday , council of sikh gurudwaras open a radio station for 1 month ( 24x7 ) constantly about sikhism ( Some discussion topics they have are very inspirational and educating ) OR even on SKY 880 , 926, 900 channels
5. When you have low self esteem or not , when you are walking/ sitting , recite waheguru in your mind .