In Stuart Lichtman's book he talks about how to set very specific objective to attract a partner.. specific to the extent of mentioning hair color and eye colour in the objective.
His technique involves a detailed process of setting an effective objective that is clear to your subconscious, dissolving any limiting belief and unconscious habit pattern that we could have developed. I feel these would really help in your case because growing with a negative person around is a surefire way to develop a lot of self-defeating beliefs which is a huge blocker to manifestation.
I have tried his method twice in other contexts and have had success.After I accomplish the current target I m working on I'm planning to attract a PERFECT partner of my own
But if you are considering to try his method be warned it takes work and effort to do his processes. But its worth it if you ask me.