Learn Portuguese (Portugal): Há meses que me sinto estagnado num ambiente tóxico. - I have felt stagnated in a toxic environment for months.

In Portuguese, when an action started in the past and is still happening now, you use Há + [time] + que followed by the present tense. While English uses the present perfect, translating literally to Portuguese sounds unnatural. The present tense sinto shows you are still feeling this way right now.

Why is the reflexive pronoun placed before the verb (me sinto) instead of after it (sinto-me)?

The word que acts as a "magnet" (a proclisis trigger) in Portuguese grammar. It forces object and reflexive pronouns to move directly in front of the verb. If you rephrased the sentence to remove the magnet, the pronoun would attach to the end: Sinto-me estagnado há meses.

If a woman were speaking, would the word estagnado change?

Yes. Even though it looks like a verb's past participle, estagnado is functioning as an adjective here to describe the speaker's state. A female speaker would change the ending to match her gender, saying estagnada.

Why is it num ambiente rather than numa ambiente?