I told my employer that I'm getting underpaid for my position. Two weeks later there's someone new starting in the position below mine. Should I be worried?

Hi, I'm approaching my 2 years working as an accountant at a small-mid sized firm getting quite underpaid for my role. I started as a graduate there.

I've talked to a recruiter and had a couple of interviews which made me realise that I could be better valued somewhere else. Around this time I also accidentally discovered that someone in the same position as me is getting 10k more than me a year.

I thought it wouldn't hurt too much to also go to my employer and express my concerns to see if I can get a pay rise.

However, I have more or less shot myself in the foot recently as my performance hasn't been up to "standard". I used to be very passionate and would have an insane output of work while still retaining great quality. Nowadays I'm just not motivated to do my best when a waiter working at a restaurant is probably earning more than me. I've also had a rough couple of months dealing with some personal issues which has also affected my performance.

Whilst the quality of my work is still great, my output just isn't there anymore. My Manager has sat me down to discuss this and has noticed this change and has advised me my performance needs to improve.

Have I made a mistake then going to my Manager asking for a pay rise? Now there's someone starting in the position below mine and am concerned they're wanting to get rid of me or at least preparing for me to leave for another firm. I guess I should get out of there quickly?