We don’t know why God would 'allow' His beloved David to commit adultery with Bathsheba in front of his servants/nation and then murder her husband Uriah, the ridicule of which for God has reverberated down through the centuries ("a man after God's own heart, eh?--tells us something about your Christian god, doesn’t it?!!") ?
Why does God allow Christians to be raped (without 'comfort' during the horrible experience)? Or have ulcers due to stress? Or to catch diseases from sin?
Why does God allow beautiful hearted Christians to go senile due to genetics?
Why does God allow preachers to molest the children in their churches?
Why did God allow my daughter to die, scarring/darkening every family Christmas for the rest of my life?
Why doesn't God heal my crippling fear of people, so I could be at peace around people, instead of always hypervigilant, waiting for the next blow?
Why did God let one of my closest family members actually attempt suicide (and nearly succeed), due to depression from his childhood relationship with a loved one?
Why did God let me wrestle with a desire for suicide DAILY for the vast majority of my life? (I visited a therapist in 1980 who told me I had the highest propensity for suicide he had seen in 15 years of counseling). It was years before I got the desires down to 'once a quarter'--but I would never have DONE IT, because it would hurt my loved ones, LIKE I HAD FELT HURT all my life--
Why, why, why?
1. EVERY CASE is so incredibly complicated, with influences, background, mitigating factors, goodness, results of choice, sin, psycho-pathologies, spiritual warfare, social forces, that I don’t often try to even FRAME THE QUESTION of 'allow'--it might not make much sense in such a complicated case. How many of the factors/influences does God 'encourage', how many does He 'permit to run their course', how many NEW factors/influences does He interject to try to 'head off'/intercept the destructive forces?Friend, these are theoretical considerations--I am not a therapist or counselor or pastor--I am just a researcher. Maybe your question would be best asked of a Christian counselor, who deals with these types of questions frequently (I suspect). I am sorry you had to PERSONALLY see the horror of 'feeling trapped and hopeless', for it is something that has been a frequent 'companion' to me over the years (even as a Christian). And your being 'scared' is probably a reasonable response--but also one that should urge you to be an 'intervener' YOURSELF, to attempt to Create 'intercepting' trajectories in the lives of others who see this Dark Seductress up close...
2. God never guarantees us that our lives will be only 'mildly painful' or 'mildly distressing'. How we deal with our problems are a MIX of His interventions, answers to our prayers, and our own choices/will/openness to correction/honesty etc... How many Christians have killed themselves AFTER HAVING RECEIVED GOD's comfort? I bet PLENTY HAVE. He probably OFFERED peace, succor, etc to (many of) these people... But they chose otherwise...I have gotten myself into messes in my life decades ago, where the option of facing up to my mistakes, making hard and unpopular choices, losing major 'face', and severing ties with friends was SCARIER than even suicide... God is not responsible to 'convince me otherwise'--this is MY mess, and He WOULD empower me THRU these hard roads--but ONLY IF I CHOSE THEM. He won't force me to choose the hard-but-true road (where He WILL comfort me), instead of the easy-but-false road of avoidance-through-suicide. "Free will" --both leading UP to the crisis and DURING the crisis--is clearly involved.
3. One other factor I realized as I pondered your question over the last couple of days. One MAJOR principle is that God doesn't normally 'interrupt' processes already in motion--He lets them finish their course ("a bruised reed he will not break. A smoldering wick he will not quench"). Bad choices will yield bad consequences--that process will continue without his intervention. However, He CAN/DOES start 'new' processes (repentance, therapy, community response) which THEMSELVES can intercept that other trajectory. Counseling is one such trajectory for those under suicidal thoughts--but if someone won't START such a trajectory (due to pride, lack of access, lack of familiarity with it, etc), then God has fewer options (e.g., conscience, a friend, government, etc). E.g., Diseases require EXTRA effort on the part of the patient, doctor, family--to intercept the trajectory/process of the malignancy. I would assume that some suicides (and murders and business failures and missed opportunities etc) might be due to His commitment to letting 'natural processes run their course'. He would be eager to intervene "INSIDE" ANOTHER PROCESS, but that process normally has to be started DOWN HERE and by ONE OF US (under His guidance and/or prompting, often).