Call your T.
Have you make any real plans? If so, call immediately and/or go to ER but if you're having "just" SUI thoughts I think (no expert- just talking from my experience here) you can try and work on it with your T (if he's up to it) without going inpatient.
Do you have any ppl in RL you feel close to? When I was feeling really down I've spent few nights at my BF's house on her sofa, then went on a vacation with other friends, move back with my mum for few weeks... Asking for help is not a weakness and you'd be surprised how many ppl (if asked) would gladly offer you their help. Most of the ppl close to you feel that you're suffering anyway and are actually relieved if they can help you eased the suffering. Please try to reach out.