Here's my advice to you.. and I say this from a position of a lot of personal experience and studying of clinical medical and pharmaceutical research:
Firstly, stop going to the doctor. You will only be wasting your time and money and you'll need both of those for what I will recommend for you. Doctors know absolutely nothing about what causes any of this. They've been trained to find a preprogrammed output to an input. They look at symptoms and find the corresponding output of a drug they've been trained is a remedy for those symptoms. The pool of data and information they use to get their prognoses is archaic and not even close to being relevant in terms of modern clinical literature.
Secondly, forget about any of these conditions or diseases that doctors have assigned to you. They mean nothing and they tell you literally nothing about the cause of the condition itself. Naming a condition is useless and not helpful at all for you. The only thing it accomplishes is that it gives you a feeling of hopelessness, making you believe that you now have this complex condition that no one knows anything about. Doctors give ridiculous names to conditions they know absolutely nothing about so that they can have the appearance that they actually know what's going on... "Well, Mr. Gunnersup, it seems you have a rare condition called lichen Planopilaris." Translation: I don't what the f*** is wrong with you, but I'm going to make it seem like I do by repeating your symptoms to you that (you're already aware you have) in the form of a series of complicated words you've never heard.
I'm assuming that before you took accutane, you had acne? If this is the case and you didn't have these "lichen Planopilaris" symptoms before taking accutane, then you don't have a naturally underlying genetic condition behind it... which is good, because it means that you can get rid of it.
Now, before I begin telling you what you need to do (and I probably should have started with this first, but I'm not going to reformat this message), you need to understand that your suicidal feelings are directly related to you feeling of hopelessness. You can fix this, but it's going to require a different kind of spirit than the one you have right now. You see, I have had many reasons to feel suicidal, but it has never gone past being thoughts that I would never act on. And this is because I don't have a spirit that will allow me to give up and, now, I actually have experience fixing these types of problems in my own body with great success. I'm going to download a lot of information on you, but for you own sake, it's important to know that you need to search every possible avenue of information and learn whatever it is that you have to learn to understand the information that you're processing. This gives you power in understanding and consequently gives you hope that you'll find the answers you're looking for if you simply continue searching no matter how you feel. What I'm going to tell you to do is going to require a lot of mental strength, but if you do it and you don't give up for any reason, you will be normal again... beyond better than normal.
Luckily, it sounds like you have not yet begun taking finasteride. Don't. Do not take a 5AR inhibitor under any circumstance. It will only introduce new problems that will be even more difficult to fix than the problem that was created by accutane. I have taken accutane and have also experienced the same symptoms. So, not only am I speaking to you from experience with 5AR inhibitors, but also from experience with the use of trans-retinoic acid (accutane). Based on what I'm seeing about the current medications that you're taking, they have all been prescribed for this skin/hair condition doctors are calling "lichen Planopilaris". Stop taking these. All of them. They will do absolutely nothing for you. They will only contribute to making your condition worse. Doxycycline will destroy the bacterial profile of you gut and wreck your body's ability to digest food properly (among other important functions of bacteria in the body) and the immunosuppressive drugs will do exactly the opposite of what you need (which is to strengthen your immune function, not weaken it).