So, today, 1 year, 10 months and 19 days later... I reached my goal weight. Help me work out maintenance!

[ThisMustBeMyDream]

I thought I had 2 more weeks to lose, but it took me by surprise this morning with a 1.5lb loss. Anyway, I'm at goal! 100lb lost in total! 42% of my body weight. Feel like I've prematurely ejaculated somewhat though as this was unexpected 🤣. But I need to get my head in to maintenance. I'd really appreciate some advice on my loose plan, and what to do with my TDEE.
So I'm 5ft 2.5 (158cm). 9st 11. I excercise 3x a week, I do around 3.5 hrs weights and 2.5 hrs cardio. I'm 40.
The tdee calculator puts me at 1496 cals to maintain when I put it as a sedentary lifestyle. If I put moderate excercise, which is 3-5 days per week, it gives me 1932 cals.
When I add my body fat percentage (27%) -which it claims is more accurate - to that calculation, it gives me 2089 cals.
I've been having 1400-1500 cals for the last 2 months, which has given me an average loss of 0.85lb a week (7lb in 8 weeks).
So, to lose 1lb a week, I'd need to be in a 500 cal deficit per day. I'm losing just under that, so I'd guess my deficit to be somewhere around 425cals. So if I aim for 1850, I think that might be more accurate than the body fat percentage one. Would others agree with this? I've never tracked calories at a maintenance level, so all this is new to me. I'm learning on the job right now!
However, am I right in thinking that perhaps it may be better to work up to that figure? I was thinking of increasing by 100 every 2 weeks so I can keep track on what my weight is doing? I'm fine to lose a bit more, as my bmi is 24.9, so I'm happy to lose a little more (I don't want to drop below a bmi of 24 though, personal preference on how I look). So I have about 5lb in wiggle room.
However, I'm also keen to get to maintenance to see if I can increase my muscle mass. My muscle mass has steadily dropped despite lifting heavy 3x per week for a full year, and eating 100-120g protein per day. I have visable muscle though as my body fat has reduced. My bmr just keeps dropping as a result and it can be a little disheartening as you are told to gain muscle mass to increase it. I know it's almost impossible to do that in a calorie deficit, but I have really tried! My legs in particular are so strong and can lift really heavy! I'm just not sure what is best to do for long term results. I get married in July, and my dress fitting is in May, so whatever I do, needs to work!

My advice would be to do exactly what you've said - increase gradually by 100 calls ish and see what happens. I lost 5 stone and got down to 130lb then I did a clean bulk and gained about 6lb of muscle, I am now maintaining at 136lb on 2500 calories but I train A LOT and I am a bit taller than you. Just take it steady and try to only change one variable at a time i.e. if you increase your calories a bit, don't vary your exercise so you know that's what has changed. Good luck and you've done so well, and you sound like you really know your stuff and have educated yourself throughout the process which will really help with maintenance.

Congratulations! It’s a great feeling isn’t it?
I just used my TDEE for maintenance, and have kept it off for around 4 years now, I don’t have my body fat percentage to input and just the Tdee figure works pretty well ime.

Also bear in mind that your body fat and muscle mass measurements might not be super accurate depending on how you are measuring them. Most smart scales are not actually super accurate. Mine show body fat of 17% and there's no way mine is that low.

First of all, CONGRADULATIONS on a fantastic achievement, that’s an incredible result, I though I’d done well at 65lb loss. I am exactly where you are now I’ve reached target so I’m staring to make little changes like swapping wholemeal bread for seeded brown, and maybe 4 slices per day instead of 2. I’m going from low fat yogurt to full fat (I’m hoping this is going to help with muscle mass as well). And occasionally if I’m out and it’s more convenient that cooking at home I will have a battered fish rather than walking past the chippy. Personally, I wouldn’t get too hung up about it. Like you say if you drop a little further so what.

Thank you for the advice 😊. I'm really looking forward to this part of the journey! I'm excited to see if I can do this, forever! I'm determined to be in that 5-10% who keep it off. I feel a mix of nerves, overwhelmed and giddy with excitement! I knew I could do it, but didn't think I would, if you know what I mean.
I've stuck to my 1500 today, but only because I'm simply not hungry for more, and don't have the appropriate foods in to increase it really. I've been planning how my meals will look to take in to account the increases in calories. I've factored in som treats (life is too short to not have something you enjoy now and then, and I've incorporated them in to my weight loss journey the whole way along anyway). I'm really excited about some of the changes I'm going to make along the way and how it can help me get stronger and leaner. I don't aspire to be the skinny girl any longer. I want to be the strong woman I am becoming!