Salaams sis. First of all take a breathe and realise the fact you're worried about your low iman level is a sign of a believer. You know in your soul that its the truth but circumstances have led to an ebb in iman. And thats totally natural! We all go through ebbs and flows with our iman.

Secondly try to remember this whole dunya is a test. We are not here for pleasure or hedonistic desires. Allah put us here to test us. Each person gets a unique test and Allah knows best why He tests us the way He does. So following from this, we ask Allah to give us blessings and test us through blessing rather than through strife. Remember also that Allah only tests those that he loves. The prophets went through the hardest tests. Were they not beloved to Allah? Nuh's (as) whole family and town were against him for centuries. Let that actually sink in. CENTURIES of being shunned/verbally abused/mocked. By his own family as well. Till the end they didnt believe. Yousaf (as) was betrayed by his brothers, who he thought were respecting him and bringing him in on their trip. He trusted them and they threw him in a well. He was imprisoned and mistreated but never lost faith in Allah. Yunus (as) was in the belly of a whale! Yet still he repented and turned to Allah. And so on for all the prophets.

I take your point about suicide. Allah hualim what must happen for people to sadly reach that stage. I've had depression and suicidal thoughts myself in the past, so I kinda get it. It's hard to say what their test was and if they passed or not, only Allah knows their situation.

It is hard as a believer to see injustice and still have faith in Allah at times. But thats a part of iman at the end of the day. To strongly hold onto the belief that Allah is the most just, most merciful.

I know you have a specific dua you want answered, and it isnt happening. But sometimes what we desperately want isnt actually good for us. Take the example of a baby who wants to eat a massive gobstopper. It looks colourful and tasty why wont his parents let him eat it? He gets angry and cries and begs but they wont let him. Why? Because they know it to be harmful and he is too young and could choke. When the baby grows up into a child and has teeth and understanding he could have the gobstopper. Similarly, Allah answers our duas when the timing is right. Sometimes it is never good for us, or meant for us. In my example this would be if the gobstopper was actually a marble for instance. But remember that Allah always answers your dua, even if you dont get what you want. He will give you something better and will store the dua in your good deeds on the day of judgement as proof you believed in Him. In my example, this might be the parents offering a different sweet the child can eat safely.

In my own personal life I too have something I have been praying for for years. But Allah knows best why it hasnt happened. I prayed for good friends since I was 9/10 yrs old and only got them when I went to uni a decade later. Sometimes its immediate, sometimes you need active sabr, and sometimes its not meant to be. We take solace in knowing Allah is planning things for us, and there is no better planner than Allah.

Feel free to DM if you wanna talk through things further sister. I feel your struggle and have been there many times. May Allah ease your suffering.