Try to commit, as you read this, to do no harm to the other. “Do no harm” includes avoiding talking with bitterness about the other, not deliberately ignoring, or not thinking about taking revenge.
I do think it may be more difficult to forgive someone who has what you call “anger issues” and then expresses that anger consistently to you. You may have to forgive on a daily basis if you are in regular contact with a person who is continuously angry. After you have forgiven to a deep enough level so that you can approach, in a civil way, this person, then it may be time to gently ask for justice. Part of justice is to ask this person, if you feel safe with this, to begin working on the anger so that you are not hurt by it.
Forgiveness does not proceed perfectly and often the outcome is not perfect. If you have done the work of forgiving and if your anger no longer controls you, then I would say that you have forgiven even if you have some anger left over.
Being together does not necessarily mean that you are reconciled. Reconciliation includes trust, but trust is earned back inch-by-inch. Does your boyfriend show you signs that he has remorse (sadness for what he did)? Does he show repentance (saying he is sorry)? Does he engage in recompense (behaviorally trying to make up for what he did and behaviorally showing he is trustworthy)? Keep these three issues in mind (remorse, repentance, and recompense) as a way to build your trust so that you can achieve a true reconciliation.
Forgiving another need not be whole-hearted. Sometimes people have anger left over and that is not an indication that there is no forgiving that is happening. Do you wish the other well? Have you forgiven to a point? For now, that may be enough. You need not be hard on yourself.
The decision to forgive usually is a cognitive act rather than an expression of the heart, of one’s emotions. One usually makes a decision to forgive without necessarily feeling compassion and love because we are not yet ready to offer these when we make the cognitive decision to forgive.
I recommend that you ask yourself what is your current level of anger—on a 1 to 10 scale—for each person. Order the people from the least anger you have to the greatest anger you have. Start with the one person with whom you have the least anger. This will allow you to get a sense of the forgiveness process and to practice that process before you get to the person who hurt you the most.