For me I was quite trusting of UK media, in particular the BBC until March 2020. I had reached the age of 60 and had been a die hard BBC fan both Radio 4 Today / PM and TV news since a child. I can still recall Alvar Lidell reading the radio news! I always thought the BBC did try very hard to be neutral and never saw the left / right bias often claimed by the Conservatives or Labour despite being a lifelong conservative.
Unfortunately, unbalanced, unquestioning Covid reporting changed all that. I imagine I wasn't the only person to lose faith in mainstream media in the light of Covid.
If you don't mind my saying so, I think that's a mistake.
I actually had a similar experience to you, but 3 months later: Like you, I had always trusted the BBC as a largely factual and politically neutral source. But that changed in June 2020 when suddenly the news got swamped by BLM and identity politics, and it very quickly seemed to me that the way the BBC (as well as most 'progressive' media outlets) were reporting all the issues around identity politics was coming from a set of values that I couldn't identify with, and since then I've largely lost faith in the BBC when it comes to communicating those values.
But here's the thing: There's a vast difference between communicating a set of values and factually reporting on what events are happening. It's perfectly possible to be doing one thing properly but not the other. I've never seen any reason to doubt that the BBC does report events as accurately as they are able, even though I feel alienated from their cultural values. In the end, the BBC does employ professional journalists; they are tasked with reporting impartially what's going on in the world, and I think you're making a huge mistake if you refuse to believe what they are saying about what's happening in Ukraine, just because you feel things went wrong over Covid (which is a totally different issue). Besides, pretty much all UK newspapers are independently reporting the same events, despite that these newspapers have very different political slants on UK politics. You may note that the Telegraph, which during Covid repeatedly questioned the 'perceived wisdom' about lockdowns etc., is likewise reporting the same events about Ukraine: That Russia has invaded a sovereign country without provocation, and their troops have set about slaughtering, raping, and torturing civilians as they go. There's really no plausible doubt that that is the main gist of what is happening, and if you try to seek out information that denies that on the pretext of somehow not taking sides, then you are deluding yourself about what is going on.
I don't know what exactly you think the BBC got wrong over Covid - I'm going to hazard a guess that that in your mind they gave too much credence to the opinions of experts about how to deal with a pandemic that at the time we didn't know enough about, and you therefore think they supported lockdowns too much. But I think you'd be wise to separate out your belief that that was a mistake from the ability of the BBC and other news sources to impartially report on what events are happening - which on the whole they do.