Hi @Pilbarian 
Thank you for sharing your wife's struggle with depression and drug dependence and how this has impacted you. I'm sorry that for many years you were made to feel that your concerns for your wife were invalid and that you were paranoid - it is terrible for one's concern about someone they love to be dismissed by the very person they are concerned for. As @Former-Member said, sometimes people with substance dependence issues, or even forms of mental illness, can be in a state of denial; this may have been the case for your wife. I am glad that your wife is finally receiving treatment at a clinic; however, I understand that this must put a lot of pressure on you trying to balance working and raising your three boys. I can also imagine that you must be battling with feelings of missing your wife, given she is receiving treatment 1600km away, but also feelings anger and resentment that it took so long for her to acknowledge your concern and receive treatment.
As @Former-Member said, while your wife is in the process of becoming more mentally stable, it may be best to put a hold on your feelings of anger and resentment. However, also as @Former-Member said, you cannot conceal such feelings forever. Thus, it is important that when you wife has stabilised, that you talk about these feelings in an open, honest and respectful way; where both parties acknowledge things they may have contributed to issues in the relationship (i.e., what emotions/behaviours from one party led to certain emotions/behaviours from other party; how this is related back to one's personal history and triggers; and how such emotions/behaviours can keep escalating back and forth). Ultimately, it can be very hard to have such a conversation without things getting emotionally heated. Therefore, if you feel like you may need some extra support with talking to your wife about such feelings, you may wish to seek couples counselling at Relationships Australia or Lifeworks. These organisations are specialised in providing treatment to couples and families - including, working through issues such as feelings of anger and resentment towards one's partner. I have listed their details, below:
Relationship Australia: Relationships Australia is a leading provider of relationship support services for individuals, families and communities.
1300 364 277
http://www.relationships.org.au/
LifeWorks: Relationship, Individual and Family Counselling, Dispute Resolution Services, Relationship & Parenting Education, Intercountry Adoption Support and more.
1300 543 396
https://lifeworks.com.au/
You may also be interested in checking out these threads that related to your current situation: "Partner in rehab" by @Kelstarkaruah; "Does anyone else have trouble expressing feelings to their partner" by @Rubyf; and "Trust" by @Ma60.
As @Former-Member said, you may also seek support from organisations specifically catered to carers - e.g., Carers Australia; MIND Australia; Wellways; etc.
I hope this information is helpful to you!
Please continue to reach out to the Forums, if you are looking for further information and support!
Kindest,
Amour_Et_Psyché