Hello fabjellybean

It's good to have you with us but I'm sorry you've been having a difficult time of it. Thank you for supplying the detail as it helps us to get a better idea of what might be going on. That said, there is a lot to get to grips with

, so first I'll try to answer your bottom line question about Utrogestan & body identical oestrogen as that's more straightforward. I'm also hypothyroid - nearly 30 years on replacement, currently T4 & T3, because of a conversion defect. Also on HRT for a few years, but postmenopause & still working on balancing the two.
I really struggle with progesterone in all its forms, but for me Utrogestan is the worst, I sense because it's too strong for me. That doesn't mean it won't suit you & many women on here get on well with it. Some use Utrogestan vaginally to minimise side effects but I can't answer your soy allergy question I'm afraid. There are also Cyclogest pessaries but I'm not sure how easily available these are, or of their ingredients other than progesterone. I think one member has had them prescribed recently, but privately. You could google them to see what exipients they contain.
The progestogen in Evorel Sequi & Conti, Norethisterone, is one of the more androgenic (testosterone derived) forms & many women find they don't feel good on this. I used Evorel Conti for a couple of years as my first HRT postmenopause & was OK on it in terms of side effects, but didn't get good absorption & consequently poor symptom relief.
As for the oestradiol products, I find I get on best with the gradual release of patches, rather than once a day application methods like Oestrogel/Sandrena & Lenzetto (spray) which can give rise to peaks & troughs in levels. We are all different in our responses, though my feeling is that hypothyroid women need as much stability as we can get in terms of other interacting meds. I also find cyclical HRT harder to combine with thyroid replacement, for the same reason, but you may have no say in that until you are postmenopause.
The fatigue, oedema, hair loss inc outer third of eyebrows, are classic for low thyroid as you know. Brain fog too, though of course this is also a meno symptom & I can't think there can be a more confusing combination than having a thyroid condition during menopause. So yes, your being undermedicated on thyroid replacement at that time could explain all those symptoms. To complicate matters I find oestrogen causes me to retain fluid, but progesterone is highly diuretic for me, again possibly because of their different effects on thyroid status, oestrogen effectively lowering active thyroid hormone & progesterone thought to boost it. So times of high oestrogen may explain the intermittent oedema.
Unfortunately even transdermal oestrogen seems to mess with thyroid levels for those of us on both T4 & T3 - we have a few members here who have experienced that, including me & my bloods demonstrate it, not just symptoms. You'll know that oestradiol causes an increase in TBG as the possible mechanism behind this situation. Though most of the scientific literature states that only oral oestrogen has this effect, it seems likely that not enough research into the complex interactions between sex hormones & thyroid status has been conducted.
The constipation, weight gain & low mood that you experienced more recently also point to low thyroid, though again all can come with menopause too.
I was found on pelvic scan to have urinary retention (as opposed to generalised fluid retention) in early peri while off T3, that resolved on restarting it, so your difficulty passing urine may be another feature of low thyroid. It can also sometimes be a consequence of constipation (hypothyroid-related or not), due to the resultant bloating affecting the mechanics of emptying the bladder. So it may help to do all you can to optimise bowel function. Unfortunately both progesterone & it's more recently been recognised - oestrogen, can slow bowel function.
The bladder & vulva pain & difficulty with tampons are suggestive of the dryness & inflammation of GSM that happens to so many of us as sex hormone levels decline, but perhaps also an indication of infection. A UTI could also cause urinary retention, so I'd speak to your GP about both bladder & vaginal symptoms if you haven't already & before you consider using progesterone vaginally. Many of us find we need both topical (vaginal) & systemic oestrogen, so I would also ask about Vagifem (tiny pessaries) or Ovestin (cream) for internal use & the weaker Estriol cream (0.01%) for external application if you opt for Vagifem internally. Sorry if I've missed mention of this in your post - I keep rereading but get sidetracked tackling something else!
Yes, I had high prolactin levels long before peri, though no one linked it with being hypothyroid at the time. I believe you are right that the two can go hand in hand. Don't quote me on that though - long time since I looked into it. I would definitely still ask your GP about it as your level is really quite high, as you say.
Low libido can be helped by getting the right balance of oestrogen & testosterone, but again this can be more complicated for hypothyroid women because of the influence of SHBG. It's also not surprising your libido should be low with all you are coping with in terms of other symptoms.
It's a long time since I was in peri & I'm hoping one of the members who's more up to speed about that stage will be along to advise on how best you can manage your HRT needs accordingly, but we are usually advised to use cyclical regimens until postmenopause.
High oestrogen will almost certainly not be helping your thyroid situation & I found the erratic fluctuations of peri to be really very difficult with the thyroid complication, so you have my sympathy.
I'm sorry this doesn't answer all you need to know, but one of the great things about the forum is that someone else will almost certainly come along to help out with the bits I haven't addressed. And perhaps with differing views on the bits I've tried to!
Meanwhile

for all you are coping with.
Wx