The good news is that it is possible to identify these beliefs and then make a conscious choice as to whether you want to let them shape your path going forward. The first step in this is awareness, you have to see the beliefs in question. Take some time to journal on this, write down your common thoughts and ask whether they are useful for you. If you struggle to find examples then simply consider any time where you have experienced a negative emotion such as frustration, anger or sadness. Then unpick these emotions to see what belief is sitting behind them. You could even google 'common limiting beliefs' to see examples from others.
Once identified it is time to test these beliefs. Have they caused you distress of some kind before? Have they prevented you from achieving something you wanted? If yes then these are limiting beliefs and you would be wise to challenge them and find swaps. Before you go there however there is an extra step. You see we often manage to skirt around dealing with these beliefs, many of which we are acutely aware of, by finding exceptions - often by shifting tenses. Take the smoker who knows it is bad for them yet continues by saying 'well it hasn't harmed me yet'. They've switched to past tense. This piece of mental trickery allows troublesome beliefs to long over stay their welcome. Enter Tony Robbins, arguably the worlds most eminent performance coach, and his 'Unleash the Power Within' event. Here he uses a technique called the Dickens Process to battle these beliefs in multiple tenses and thus give no room to hide.
The Dickens reference is to the 3 ghosts from 'A Christmas Carol' as this exercise asks you to think about the beliefs you've identified in past, present and future tense. Simply ask yourself 'How has this belief harmed me and those I care about in...' and consider this for the past, where you are now and then 1, 3, 5 and 10 years into the future. By working through this you will have to face up to the stark reality of what these beliefs are costing you and only then will you be forced to change them as there is no where left to hide them. Be warned that this can be an emotional process, many of us hold limiting beliefs for many years and some can come from traumatic experiences. Don't be afraid of this, be willing to be vulnerable with it, but do seek professional support if you think you may need it.
The final piece of this is to replace these limiting or faulty beliefs with ones that are more useful for you. Again it is important to take your time here. Journal on it and explore possibilities, playing out how they might work for you. See it like test driving a car or buying a suit. You are going to have these beliefs for many years to come, potentially forever, so make sure they are a good fit.
When I was younger I used to get frustrated as I'd work hard and not always get rewarded for this. Unpicking this I could see that i had the beliefs of 'life should be fair', 'work hard and you will be rewarded' and 'you get what you deserve'. Whilst seemingly reasonable beliefs they caused me lots of issues. Over time I was able to replace them with the beliefs 'life isn't fair and that's ok', 'You can only control the controllables' and 'find a way to love the process'. Whilst some days I still need to remind myself of these it generally means I navigate life now with much less frustration.
So, in summary, if you find yourself experiencing negative emotions then it is a red flag that you have some unhelpful beliefs in operation. Take a step back to identify these and put them through the Dickens process. See and feel what these beliefs have done to you in the past, what they are doing to you now and what they could do to you in the future. Once faced with these realities you are in a position to make the changes and find more helpful beliefs. At first this swap will take effort, you will need to constantly remind yourself and may find the old beliefs creep back in from time to time. Simply remember the process, picture that future self and swap to the helpful belief. Over time this process will be come automatic and you will start to reap the rewards of your new beliefs.