This is not want you want to hear but I was in the same position two years ago.
I left a long standing job because I was being undervalued, underpaid, micro managed and over criticised. I didnt want to leave but I saw no choice and that is how the culture was going there. More people have left since me.
The new job was a well established place but much smaller and less financially secure and less resources. It was a disaster from start to finish. I was treated very badly. Far far worse than I was ever treated in my old job. It was an utter nightmare. Because they were less financially secure I may have got a pay rise to go there but I realised there had been no payrises or bonuses for years in there and pension was only 1% where it had been 6% at my old job.
The way it was run made it impossible for you to do well. The work loads were too high and non existent support.
I complained. Lots. I ended up out on my arse. Literally, they came to me one day and said get out, your taxi is downstairs. I found out later, I should have shut my mouth as they dont care what you think and they knew I was right and they saw me as a liability.
It took me 5 months to get another job. Another company that was newer and didnt have the expertise or resources. I got poor quality work. I said something. I asked for better work. After less than 3 months they said we dont need you after all, out.
Im unemployed again but have some interviews coming up.
If you want the honest truth, however bad my original job was, I should have stayed put. The stress and hassles over the last two years have had a detrimental effect on my mental well being.
Ask for a meeting with the MD. Tell them exactly what you said here. If they've any balls they will listen to you and act. Maybe you'll get a promotion. It sounds like you're already wasted there.
Will all due respect to Violet, this is very bad advice. Go into a new job all guns blazing...I made that mistake and they did not take kindly.
Also are you aware that you cannot make a claim for unfair dismissal unless you have worked somewhere for 2 years? If they dont like you, they can just get rid of you with no reason or consequences.
Yes, I would be very very worried if I were you. Start looking for new jobs now.