Purging is not backed by data so I doubt it's that, but there's a small chance it could simply be that.

A few thoughts on what else it might be:

• Scrubbing the skin too much or irritating it in any other way should be avoided. Make sure you're always using a featherlight touch. I have seen skin very much like yours (after pics) from irritation or over-scrubbing.
• Sunscreens can break people out pretty badly. Very few are non-comedogenic in my experience. Perhaps you could try wearing a wide brimmed hat instead of sunscreen for a while until you get clear and then add sunscreen into your regimen and see if you stay clear? You do need to protect your skin, particularly as you start on tretinoin, but I worry that the sunscreen might not be great. Which one are you using in particular and do you have an ingredient list you can share for it?
• You may be using too much moisturizer. Two layers of it sounds like you might be overly occluding your skin and clogging pores. Again, which moisturizer are you using and can you share an ingredient list?

It can be difficult to tell the difference between purging and breaking out when you start using a new skincare product. Purging is a temporary breakout that can happen when you start using a new product that contains active ingredients, such as benzoyl peroxide or salicylic acid. These ingredients can help to exfoliate the skin and remove dead skin cells, which can lead to breakouts. However, these breakouts are usually not as severe as regular breakouts and should clear up within a few weeks.

Breaking out, on the other hand, is a more persistent breakout that can happen for a variety of reasons, such as hormonal changes, stress, or a reaction to a product. If you are breaking out, the breakouts will usually not clear up on their own and may require treatment with medication or other products.

Here are some ways to tell the difference between purging and breaking out:

• Purging usually starts within a few days or weeks of starting a new product.
• Purging typically affects areas of the skin that are prone to breakouts, such as the T-zone.
• Purging breakouts are usually not as severe as regular breakouts.
• Purging breakouts should clear up within a few weeks.
• Breaking out can happen at any time and can affect any area of the skin.
• Breaking out breakouts can be severe and may require treatment.
• Breaking out does not usually clear up on its own.

If you are not sure whether you are purging or breaking out, it is best to see a dermatologist. They can help you to determine the cause of your breakouts and recommend the best course of treatment.

Here are some tips to help prevent purging:

• Start with a low concentration of the active ingredient.
• Gradually increase the concentration over time.
• Use the product as directed.
• Avoid using other products that can irritate the skin.
• Be patient. Purging can take a few weeks to clear up.

If you are experiencing purging, there are a few things you can do to help soothe your skin:

• Use a gentle cleanser.
• Apply a moisturizer to help keep your skin hydrated.
• Avoid using harsh exfoliators.
• Use a sunscreen with an SPF of 30 or higher to protect your skin from the sun.

If you are concerned about purging, talk to your doctor or dermatologist. They can help you to determine the best course of action for your skin.

Can't really tell you should ask your derm. However, I really recommend the new Accure Laser for Active Acne. I tried it because I was hesitant on taking Accutane cause of the side effects. Definitely helping a lot. I've only had 2/4 sessions so far and I can see a lot of progress.
Hope this helps.