There is no right time to open your heart to a new dog. There is only your time.
Some people feel ready within months. Some people take years. Some people never feel ready, and then a dog finds them. Some people decide that the grief they felt was the most honest tribute they could offer the dog they lost, and that dog is the most honest continuation of the love they have to give.
None of these paths is wrong. The only mistake is getting another dog before you are genuinely ready, not to meet a social expectation, not to fill the silence, not to make the grief go away faster. A dog deserves to be wanted, not deployed.
If and when you feel ready, here is a list of reputable Los Angeles area rescues to help you in your fostering and/or adoption journey.
Opening your heart is not a betrayal of the one you lost.
Your capacity to love is not finite.
Loving a new dog does not subtract anything from the love that came before.
It honors it.