Before asking what to do differently, it will be great to get a full picture of what you've got as a norm right now.
What we know:
You maintain 1300-1650 cals for 4-5 months, losing 18 lbs in the process (10% Body weight)
Normally you do not experience hunger
You had a quick regain of 4 lbs
You have a physically demanding job and do some slow movement
You have a lot of stress in your life
Relaxation techniques lead you to depressive soul-searching
you have a past history of reverting the weight loss
What we do not know:
Your macros and food choices (save for pumpkin seeds)
Alcohol, dairy, fruits
which supplements you are taking, including seaweeds, bone broth?
did you recalculate your BMR to account to 20 lbs loss, and did you use Mifflin's equation to calculate it?
Here is what I can tell you: 10% loss in body weight is a normal point to plateau. Pushing past this plateau is possible but often results in Bad Things Happening. I honestly believe that 4 lbs you are seeing is not a trend but a budge/some sort of re-balance. Changing one variable for 2 weeks may help you to stabilize your weight and after that start losing. The easiest variable in your case is macros, probably. Do a fat fast. Or, if your fats are high jack up protein. Drop all fruit or dairy if you are using it. Change just one thing and stick for 2 weeks. See what's up.
I highly recommend Susan Alber's book "But I deserve this chocolate!" as it has a very short summary of a lot of psychological traps and how to avoid them by changing your thinking. I know, it irritates you and is too new agey and all that, but most people fail to lose weight not because they follow a bad diet or do bad exercise. They do it because they pay little attention to what they are thinking and where it takes them.
Do not do a radical change. One thing. Stick. See what happens. Keep both eyes on the road, not one eye on the goal, or it will take longer to walk to the destination.