[MtF] Some questions about losing weight and HRT!

Hey :)

So, I have decided I want to transition as soon as possible. I'll get an appointment to a therapist this week, and probably start some sessions already. I feel like I am going to spill the beans right away to see if I can make things go faster. (enough of waiting, ugh. Just give me my goddamn rainbow pills.)

BUT, thing is: I've been doing a treatment to lose weight for some time now, so I'd like a few advices. I've never been much active, but since I've decided I am going to transition, I have been exercising quite a lot. Does 30~60 minutes (Daily) of stationary bike (alternating between moderate and intense pace) will help me lose weight without gaining any muscles? I downloaded MyFitnessPal (Thank you for this recommendation! Really great app) and have been eating between 1200-1400 calories a day. I am not sure how many kg I will lose per week, but I'd like to lose a lot of weight.

I am 19yrs old, weighting 90kg/198lbs and am 162cm/5'4 tall. I plan to lose at least 30kg/60lbs on the next few months, but I am not sure if HRT will affect my progress. I feel like I am at a good age to start HRT and don't want to wait more time than I already did, but I am not sure if I would continue to lose weight (and muscles, please) on it, and I feel like starting with my weight now would be pretty shitty. Should I go for it, anyways?( Gonna keep doing what I am doing to lose weight!)

So, cardio (stationary bike - and ocasionally dancing to Paramore lol), low cal diet (not anything radical like Keto, just eating less and being careful) and overall trying to be positive but not going insane. How are my plans? What should I expect?