Transfem

Since your body (almost certainly) produces estrogen already, your best bet is to see a doctor and get blood labs to check your estrogen levels to see if they're too low and move forward from there.

I think you might be making some bad assumptions about the role in estrogen in helping you feel more feminine - it's entirely possible your body already is producing enough estrogen, and taking DIY estrogen will not only not help, but could cause negative symptoms for you.

Applying what the transfem community is doing to suppress the production of testosterone from their testes, and to supply the estrogen their body is not producing, to yourself is not likely to give you the results you want.

If you have already completed blood labs and know you have too little estrogen, and you are struggling to get HRT as a cis person, I could understanding turning to DIY, but as I understand it, the gatekeeping for HRT for cis people with various health complaints (PCOS, menopause, etc.) is nothing like that for trans HRT in the UK - you shouldn't be seeking care through GenderGP (which is specifically for trans folks) if you're assigned female at birth and looking for estrogen replacement therapy, you just need to see a normal endocrinologist or gynecologist who will be happy to provide you with an estrogen Rx if your estrogen levels are actually low. It should be affordable and the wait shouldn't be crazy (right now the wait time trans youth face is like 25 years ... it's basically just a complete lack of access to care).

Judging by your posts you are in a very bad place right now and you're struggling with a lot of issues related to your self image and your body. I'm not so sure that HRT will do what you want it to do. If your hormone levels are fine then your fat distribution isn't likely to become any more feminine. If there is something wrong with your levels, it will be because of some underlying issue, in which case HRT could even make things worse.

As a cis woman in the UK, you have access to HRT via a GP, which would enable you to get proper specialist support that isn't readily available to us, and everything (other than your prescription) would be completely free. Superdrug & Boots also provide affordable private assessment & support for hormone issues that are exclusive to cisgender women. Handling this via a GP is something I really recommend. If you are unable to get an appointment in the morning, try calling anyway as they occasionally have cancellations available later on. If all else fails, 111 can make an Out of Hours appointment, either with your GP or with a OOH doctor, or they can refer you to mental health services for immediate support.

Places like GenderGP are aimed at trans people who are currently unable to use regularly accessible services, and are significantly more expensive & less reputable as a result. They are also overburdened, with waiting times that significantly exceed a GP.

If you do wish to take hormones DIY, I urge you to take things a bit slower and read up on how to do this safely. Research what HRT actually does and why, and be aware that we take regular blood tests to make sure our levels are okay. If possible, try to find resources specific to cisgender women, as they would be able to provide more guidance in ways that we're unable to.

I wish you the very best, and I hope you're able to get the support you need.

Not specific to the UK, but if you're going to DIY and have concerns about continued legal access, I highly recommend buying raws and compounding your own injectable. 20g of EEn (estradiol enanthate) will likely last you a lifetime even if you're doing monotherapy. ~200£ will buy you a supply that can't be taken away.
Hrtcafe.net and Lena's Guide have good info.